Core Connections Integrated 3
Core Connections Integrated 3
1st Edition
Brian Hoey, Judy Kysh, Leslie Dietiker, Tom Sallee
ISBN: 9781603283939
Textbook solutions

All Solutions

Page 3: Questions

Exercise 1
Step 1
1 of 1
To solve this exercise, follow the following steps:
1. Receive a card with a function from your teacher.
2. Find the other students in your class who have the same value after evaluating their function.
3. Justify to your teammates how you know your value matches their values.
Exercise 2
Step 1
1 of 2
In this exercise, we are going to have a fun project, building shapes out of yarn!

*Let’s get started!*

Step 2
2 of 2
To do this, follow the following steps:

1. Invite your team to sit together.
2. Introduce yourselves.
3. Give each member of your team a specific role card, where every student is responsible for completing the lesson.
4. Work with your team to make each of the shapes you see below out of a single loop of yarn. Try picking a line in the image, and following it with your finger while pulling the yarn so they resemble each other.
5. Call your teacher over to show off your accomplishment.

Are you done? Congratulations and good job!

Exercise 3
Step 1
1 of 3
textbf{(a)} Below is sequence of machines:
$$g(x) rightarrow k(x) rightarrow h(x) rightarrow f(x)$$
Hence we obtain the function $f circ h circ k circ g(x)$.\\
Putting $x=6$ in $g(x)$:
begin{align*}
g(6)&=-(6-2)^2\
&=-(4)^2\
&=-16
intertext{Putting $x=g(6)=-16$ in $k(x)$:}
k(-16)&=-dfrac{(-16)}{2}-1\
&=8-1\
&=7
intertext{Putting $x=k(-16)=7$ in $h(x)$:}
h(6)&=2^7-7\
&=128-7\
&=121
intertext{Putting $x=h(7)=121$ in $f(x)$:}
f(121)&=sqrt{121}\
&=11
end{align*}\
Step 2
2 of 3
textbf{(b)} Below is sequence of machines:
$$f(x) rightarrow g(x) rightarrow k(x) rightarrow h(x)$$
Hence we obtain the function $f circ h circ k circ g(x)$.\\
Putting $x=64$ in $f(x)$:
begin{align*}
f(64)&=sqrt{64}\
&=8
intertext{Putting $x=f(64)=8$ in $g(x)$:}
g(8)&=-(8-2)^2\
&=-(6)^2\
&=-36
intertext{Putting $x=g(8)=-36$ in $k(x)$:}
k(-36)&=-dfrac{(-36)}{2}-1\
&=18-1\
&=17
intertext{Putting $x=k(-36)=17$ in $h(x)$:}
h(17)&=2^{17}-7\
&=131072-7\
&=131065
end{align*}\
Result
3 of 3
(a) $g(x) rightarrow k(x) rightarrow h(x) rightarrow f(x)$ (b) $f(x) rightarrow g(x) rightarrow k(x) rightarrow h(x)$
Exercise 4
Step 1
1 of 2
Let us consider the given function
$$
color{#4257b2} f(x)=frac{1}{x-2}.
$$

a.

We need to calculate the value of $f(4)$. Therefore, we substitute $x=4$ in the given function and calculate the output. This gives

$$
f(4)=frac{1}{4-2} = frac{1}{2}.
$$

Therefore
$$
color{#c34632} f(4)=frac{1}{2}.
$$

b.

We need to find the value of $x$ for which $f(x)=1$. Therefore, we substitute $f(x)=1$ in the equation of the given function and calculate $x$. This gives

$$
1=frac{1}{x-2} implies x-2=1 implies x=3
$$

Therefore the input that gives an output of $1$ is
$$
color{#c34632} x=3.
$$

Result
2 of 2
$$
text{a.} hspace{3mm} f(4)=frac{1}{2} hspace{20mm} text{b.} hspace{3mm} x=3
$$
Exercise 5
Step 1
1 of 5
The inner working of the machine is:

$f(x)=x^2+2x+1$

Step 2
2 of 5
a-

If 3 is dropped in the machine:

$f(3)=3^2+2(3)+1=9+6+1=16$

The output is 16

Step 3
3 of 5
b-

If -4 is dropped in the machine:

$f(-4)=(-4)^2+2(-4)+1=16-8+1=9$

The output is 9

Step 4
4 of 5
a-

If -22.872 is dropped in the machine:

$f(-22.872)=(-22.872)^2+2(-22.872)+1=523.1284-45.744+1=478.384$

The output is 478.384

Result
5 of 5
a-          For the input of 3, the output is 16

b-          For the input of -4, the output is 9

c-          For the input of -22.872, the output is 478.384

Exercise 6
Step 1
1 of 4
$g(x)=sqrt {x-5}$          (Given function machine $g$)

$h(x)=x^2-6$          (Given function machine $h$)

$x=6$          (Input value)

Step 2
2 of 4
a-

Assuming the first function machine is $g(x)$ and the second is $h(x)$

$g(6)=sqrt {6-5}=sqrt {1}=1$

$h(1)=1^2-6=1-6=-5 neq 5$

Then this is not the correct order.

Assuming the first function machine is $h(x)$ and the second is $g(x)$

$h(6)=6^2-6=36-6=30$

$g(30)=sqrt {30-5}=sqrt {25}=5$

Then, Angelica must put the function machine $h(x)$ in the first and $g(x)$ in the last.

Step 3
3 of 4
b-

Yes it is possible to get a final output of $-5$. by putting the function machine $g(x)$ in the first and the function machine $h(x)$ in the last.

$g(6)=sqrt {6-5}=sqrt {1}=1$

$h(1)=1^2-6=1-6=-5$

Result
4 of 4
a-          Angelica must put the function machine $h(x)$ in the first and $g(x)$ in the last to get a final output of 5 from the input of 6.

b-          It is possible for Angelica to get a final output of $-5$. by putting the function machine $g(x)$ in the first and the function machine $h(x)$ in the last.

Exercise 7
Step 1
1 of 5
a-          The graph of the function $y=-2x+7$

Exercise scan

Step 2
2 of 5
b-          The graph of the function $y=dfrac {3}{5}x+1$

Exercise scan

Step 3
3 of 5
c-          The graph of the function $3x+2y=6$

Exercise scan

Step 4
4 of 5
d-          The graph of the function $y=x^2$

Exercise scan

Result
5 of 5
a-          The graph of the function $y=-2x+7$

b-          The graph of the function $y=dfrac {3}{5}x+1$

c-          The graph of the function $3x+2y=6$

d-          The graph of the function $y=x^2$

Exercise 8
Step 1
1 of 4
a-          The graph of the part (d) is a curved line opens upwards but the other three graphs are straight lines.
Step 2
2 of 4
b-          What makes the equation different is that the power of the variable $x$ is 2. While in the other equations the power of the variable $x$ is 1.
Step 3
3 of 4
c-          The graph of part (d) is called Parabola.
Result
4 of 4
a-          The graph of the part (d) is a curved line opens upwards but the other three graphs are straight lines.

b-          The power of the variable $x$ is 2. While in the other equations the power of the variable $x$ is 1.

c-          The graph of part (d) is called Parabola.

Exercise 9
Step 1
1 of 3
a-

$4(x-1)-2(3x+5)=-3x-1$          (Write the equation)

$4x-4-6x-10=-3x-1$          (Distributive property)

$4x-6x+3x=4+10-1$          (Grouping similar terms)

$x=13$          (Solve for $x$)

Step 2
2 of 3
b-

$3x-5=2.5x+3-(x-4)$          (Write the equation)

$3x-5=2.5x+3-x+4$          (Distributive property)

$3x-2.5x+x=5+3+4$          (Grouping similar terms)

$1.5x=12$          (Simplify)

$x=8$          (Solve for $x$)

Result
3 of 3
a-          $x=13$

b-          $x=8$

Exercise 10
Step 1
1 of 5
a.

Let us multiply the given expression by multiplying each monomial form the first bracket with each monomial from the second bracket

$$
begin{align*}
(5m-1)(m+2) &= 5m cdot (m+2) -1 cdot (m+2) \
&= 5m cdot m + 5m cdot 2 -1 cdot m -1 cdot 2 \
&= 5m^2 +10m -m -2 \
&= 5m^2 +9m -2.
end{align*}
$$

Therefore
$$
color{#c34632} (5m-1)(m+2)=5m^2 +9m -2.
$$

Step 2
2 of 5
b.

Let us multiply the given expression by multiplying each monomial form the first bracket with each monomial from the second bracket

$$
begin{align*}
(6-x)(2+x) &= 6 cdot (2+x) -x cdot (2+x) \
&= 6 cdot 2 + 6 cdot x -x cdot 2 -x cdot x \
&= 12 +6x -2x -x^2 \
&= -x^2+4x+12.
end{align*}
$$

Therefore
$$
color{#c34632} (6-x)(2+x)=-x^2+4x+12.
$$

Step 3
3 of 5
c.

Let us multiply the given expression

$$
begin{align*}
(5x-y)^2 &=(5x-y)(5x-y) \
&= 5x cdot (5x-y) -y cdot (5x-y) \
&= 5x cdot 5x + 5x cdot (-y) -y cdot (-5x) -y cdot (-y) \
&= 25x^2 -5xy -5xy +y^2 \
&= 25x^2 -10xy +y^2.
end{align*}
$$

Therefore
$$
color{#c34632} (5x-y)^2= 25x^2 -10xy +y^2.
$$

Step 4
4 of 5
d.

Let us multiply the given expression by multiplying the first monomial with each monomial from the bracket

$$
begin{align*}
3x(2x-5y+4) &= 3x cdot 2x + 3x cdot (-5y) +3x cdot 4 \
&= 6x^2 -15xy +12x.
end{align*}
$$

Therefore
$$
color{#c34632} 3x(2x-5y+4)= 6x^2 -15xy +12x.
$$

Result
5 of 5
$$
begin{align*}
&text{a.} hspace{3mm} (5m-1)(m+2) =5m^2 +9m -2 \
&text{b.} hspace{3mm} (6-x)(2+x) =-x^2+4x+12 \
&text{c.} hspace{3mm} (5x-y)^2 = 25x^2 -10xy +y^2 \
&text{d.} hspace{3mm} 3x(2x-5y+4) = 6x^2 -15xy +12x \
end{align*}
$$
Exercise 11
Step 1
1 of 1
To apply this exercise, follow the following steps:
1. Prepare the Collaborative Learning Expectations essay.
2. Choose a member of your team to read it.
3. Ask your friend to read it out loud.
Exercise 12
Step 1
1 of 6
a.

Let us sketch a function that has a domain of all real numbers between and including $-3$ and $10$ and a range of all real numbers between and including $-4$ and $6$. Therefore, we can write:

$$
-3 leq x leq 10 hspace{6mm} text{and} hspace{6mm} -4 leq y leq 6.
$$

We draw the lines

$$
x=-3, hspace{6mm} x=10, hspace{6mm} y=-4 hspace{6mm} text{and} hspace{6mm} y=6.
$$

as seen on graph below. Any function that is inside that rectangle including the boundries is our wanted function.

Exercise scan

Step 2
2 of 6
There is an infinite number of possible functions. Here are two exemples.Exercise scan
Step 3
3 of 6
Exercise scan
Step 4
4 of 6
b.

Let us sketch a function that has a domain of all real numbers and a range of values $2$,$4$,$5$ and $8$.. Therefore, we can write:

$$
-infty < x < infty hspace{6mm} text{and} hspace{6mm} y in { 2,4,5,8 }.
$$

There is a big number of possible solutions. Let us give two examples.

Exercise scan

Step 5
5 of 6
Exercise scan
Result
6 of 6
The functions are sketched as instructed.
Exercise 13
Step 1
1 of 3
My team’s function is the radical function$colon$          $y=2 cdot sqrt {9-x}-4$

The below is the graph of the function.

The key points of the graph are$colon$

The starting point of the graph$colon$          $(9,-4)$

The x-intercept$colon$          $(5,0)$

The y-intercept$colon$          $(0,2)$

There are so many integer inputs that give integer values as output. such as$colon$

$(9,-4), (8,-2), (5,0), (0,2)$ and $(-7,4)$

The values of $x$ that do not make sense are the values that are out of the domain.

The values of $y$ that do not make sense are the values that are out of the range.

The domain is$colon$          $x leq 9$

The range is$colon$          $y geq -4$

It is clear from showing the key point accurately that the graphing calculator shows an accurate graph.

Step 2
2 of 3
Exercise scan
Result
3 of 3
The key points of the graph are$colon$          $(9,-4)$,          $(5,0)$ and $(0,2)$

Integer inputs that give integer values as output. such as$colon$          $(9,-4), (8,-2), (5,0), (0,2)$ and $(-7,4)$

The values of $x$ that make sense are the values of the domain$colon$          $x leq 9$

The values of $y$ that make sense are the values of the range$colon$          $y geq -4$

It is clear from showing the key point accurately that the graphing calculator shows an accurate graph.

Exercise 14
Step 1
1 of 1
To apply this exercise, follow the following steps:
1. Solve problem 1-13.
2. Rewrite your answer under the construction that given in this exercise.
3. Ask your friend to read it out loud.
Exercise 15
Step 1
1 of 4
If the x-intercepts are two points $(-4, 0)$ and $(2, 0)$ then function is a quadratic function.

Since the range of the function is:          $y geq -8$, then the parabola of the equation opens upwards and the vertex is a minimum

x-coordinate of the vertex $x_v=dfrac {x_1+x_2}{2}$ where $x_1$ and $x_2$ are the x-coordinates.
$x_v=dfrac {-4+2}{2}=-1$

The vertex is the point $(-1, -8)$

Substituting for the three points x-intercepts $(-4, 0)$ and $(2, 0)$ and the vertex $(-1, -8)$ in the general form of the quadratic equation:          $y=ax^2+bx+c$
$0=a(-4)^2+b(-4)+c$

$0=16a-4b+c$          (1)

$0=a(2)^2+b(2)+c$

$0=4a+2b+c$          (2)

$-8=a(-1)^2+b(-1)+c$

$-8=a-b+c$          (3)

Subtracting (2) from (1)

$0=16a-4b+c$          (1)

$0=4a+2b+c$          (2)

——————————-

$0=12a-6b$          (4)

Subtracting (3) from (2)

$0=4a+2b+c$          (2)

$-8=a-b+c$          (3)

——————————-

$8=3a+3b$          (5)

Step 2
2 of 4
Solving the system of equation (4) and (5)

$0=12a-6b$          (4)

$8=3a+3b$          (5)

Multiply (5) by 2 and add to (4)

$0=12a-6b$          (4)
$16=6a+6b$          (5)
$18a=16$

$$
a=dfrac {8}{9}
$$

Substituting in (4)

$0=12 times dfrac {8}{9}-6b$          (4)
$6b=4 dfrac {8}{3}$

$6b=dfrac {32}{3}$

$b=dfrac {32}{18}$

$$
b=dfrac {16}{9}
$$

Substituting for $a$ and $b$ in (1)

$0=16(dfrac {8}{9})-4(dfrac {16}{9})+c$          (1)

$c=-dfrac {4 times 16}{9}$

$$
c=-dfrac {64}{9}
$$

The equation is:

$$
y=dfrac {8}{9}x^2+dfrac {16}{9}x-dfrac {64}{9}
$$

It is only one solution.

Step 3
3 of 4
$$
y=dfrac {8}{9}x^2+dfrac {16}{9}x-dfrac {64}{9}
$$

Exercise scan

Result
4 of 4
The equation is:          $y=dfrac {8}{9}x^2+dfrac {16}{9}x-dfrac {64}{9}$

It is only one solution.

Exercise 16
Step 1
1 of 3
The initial deposit is 10 cents and the daily increase is 2 cents.\
The below is the table of the values.\
begin{center}
begin{tabular}{|l|l|}
hline
x & y \ hline
0 & 10 \ hline
1 & 12 \ hline
2 & 14 \ hline
3 & 16 \ hline
4 & 18 \ hline
5 & 20 \ hline
end{tabular}
end{center}
It can be represented by the function$colon$\
$y=2x+10$\
($x$ represents the days. qquad $y$ represents the balance after $x$ days)\
\
The below is the graph of the function.\
Step 2
2 of 3
Exercise scan
Result
3 of 3
The function $y=2x+10$ represents the relation between the days $x$ and the balance $y$
Exercise 17
Step 1
1 of 2
$f(x)=dfrac {1}{x}$          (Given function)

a-          $f(dfrac {1}{2})=1 div dfrac {1}{2}=2$

b-          $f(dfrac {1}{10})=1 div dfrac {1}{10}=10$

c-          $f(0.01)=1 div dfrac {1}{100}=100$

d-          $f(0.007)=1 div dfrac {7}{1000}=dfrac {1000}{7}$

Result
2 of 2
a-          $f(dfrac {1}{2})=2$

b-          $f(dfrac {1}{10})=10$

c-          $f(0.01)=100$

d-          $f(0.007)=dfrac {1000}{7}$

Exercise 18
Step 1
1 of 5
begin{center}
begin{tabular}{|l|l|}
hline
x & y \ hline
3 & 8 \ hline
10 & 29 \ hline
20 & 59 \ hline
end{tabular}
end{center}
The above table represents the given data. By graphing the given data on the graphing calculator, we get straight line as in the graph below.\
\
Step 2
2 of 5
a-

When the input of the machine is 5, The output is 14

When the input of the machine is -1, The output is -4

By using the regression function of the graphing calculator, we find the function that represents the machine work is:

$$
y=3x-1
$$

Step 3
3 of 5
b-

The equation of Terri’s machine is:

$$
y=3x-1
$$

Step 4
4 of 5
Exercise scan
Result
5 of 5
a-          For the input of 5, The output is 14          For the input of -1, The output is -4

b-          The equation of Terri’s machine is:          $y=3x-1$

Exercise 19
Step 1
1 of 4
For solving the quadratic equation, we use the quadratic formula:

$x_{1,2}=dfrac {-b pm sqrt {b^2-4ac}}{2a}$

Step 2
2 of 4
a-

$x^2-8x+15$          (Given)

$a=1$

$b=-8$

$c=15$

Solving by the quadratic formula

$x_{1,2}=dfrac {-(-8) pm sqrt {(-8)^2-4(1)(15)}}{2(1)}$

$x_{1,2}=dfrac {8 pm sqrt {64-60}}{2}$

$x_{1,2}=dfrac {8 pm sqrt {4}}{2}$

$x_{1,2}=dfrac {8 pm 2}{2}$

$x_{1}=dfrac {10}{2}=5$ and $x_{2}=dfrac {6}{2}=3$

Step 3
3 of 4
b-

$2x^2-5x-6$          (Given)

$a=2$

$b=-5$

$c=-6$

Solving by the quadratic formula

$x_{1,2}=dfrac {-(-5) pm sqrt {(-5)^2-4(2)(-6)}}{2(2)}$

$x_{1,2}=dfrac {5 pm sqrt {25+48}}{4}$

$x_{1,2}=dfrac {5 pm sqrt {73}}{2}$

$x_{1} approx 3.39$ and $x_{2} approx -0.89$

Result
4 of 4
a-          The solutions of the equation $x^2-8x+15$ are $x_{1}=5$ and $x_{2}=3$

b-          The solutions of the equation $2x^2-5x-6$ are $x_{1} approx 3.39$ and $x_{2} approx -0.89$

Exercise 20
Step 1
1 of 4
a-

When graphing an equation such as $y=3x-5$, The variable $y$ depends on the variable $x$.

Variable $x$ is independent. and variable $y$ is dependent.

Step 2
2 of 4
b-

Temperature is the dependent variable. and the time of the day is the independent variable.

Temperature changes according to the time of the day.

Step 3
3 of 4
c-

An approximate graph for the relation between the temperature and the time of the day.

Time of the day is represented on the x-axis and the temperature is represented on the y-axis.Exercise scan

Result
4 of 4
a-          Variable $x$ is independent. and variable $y$ is dependent.

b-          Temperature is the dependent variable. and the time of the day is the independent variable.

Exercise 21
Step 1
1 of 5
a.

Let us factor the expression completely. We can rewrite the middle monomial in a form of a sum or difference of two monomials. Hence, our expression now has 4 monomials which we could pair ad factorize. We have

$$
begin{align*}
x^2-x-72 &= x^2+8x-9x-72 \ &=x cdot (x+8) -9 cdot (x+8) \ &= (x+8)(x-9).
end{align*}
$$

Therefore,
$$
color{#c34632} x^2-x-72=(x+8)(x-9).
$$

Step 2
2 of 5
b.

Let us factor the expression completely. We can take the common factors in front of the bracket. We have

$$
begin{align*}
6x^2+48x &= 6 cdot x cdot x + 6 cdot 8 cdot x \ &=6x cdot (x+8) \ &= 6x(x+8).
end{align*}
$$

Therefore,
$$
color{#c34632} 6x^2+48x=6x(x+8).
$$

Step 3
3 of 5
c.

Let us factor the expression completely. We can rewrite the middle monomial in a form of a sum or difference of two monomials. Hence, our expression now has 4 monomials which we could pair ad factorize. We have

$$
begin{align*}
x^2-8x+16 &= x^2-4x-4x+16 \ &=x cdot (x-4) -4 cdot (x-4) \ &= (x-4)(x-4) \ &=(x-4)^2.
end{align*}
$$

Also we could have used the identity

$$
color{#4257b2} a^2-2ab+b^2=(a-b)^2.
$$
We now have

$$
begin{align*}
x^2-8x+16 &= x^2-2 cdot x cdot 4 +4^2 \ &= (x-4)^2.
end{align*}
$$

Therefore,
$$
color{#c34632} x^2-8x+16=(x-4)^2.
$$

Step 4
4 of 5
d.

Let us factor the expression completely. We can use the difference of two squares identity

$$
color{#4257b2} a^2-b^2=(a-b)(a+b).
$$
We now have

$$
begin{align*}
x^2-49 &= x^2-7^2 \ &= (x-7)(x+7).
end{align*}
$$

Therefore,
$$
color{#c34632} x^2-49 =(x-7)(x+7).
$$

Result
5 of 5
$$
begin{align*}
&text{a.} hspace{3mm} x^2-x-72=(x+8)(x-9) \
&text{b.} hspace{3mm} 6x^2+48x =6x(x+8) \
&text{c.} hspace{3mm} x^2-8x+16 = (x-4)^2 \
&text{d.} hspace{3mm} x^2-49 = (x-7)(x+7) \
end{align*}
$$
Exercise 22
Step 1
1 of 3
Let us consider the given function $$color{blue} f(x)=sqrt{x} -2.$$
We can now make the table of the function.
begin{center}
begin{tabular}{ |c|c|c|c|c|c|c| }
hline
x & 0 & 1 & 4 & 9 & 16 & 25 \
hline
y & -2 & -1 & 0 & 1 & 2 & 3 \
hline
end{tabular}
end{center}
And now we can draw the graph. \

Exercise scan

Step 2
2 of 3
Now we can fully describe the graph.

The domain of the function are all nonnegative real numbers, we can write $x geq 0$.

The range of the function are all real numbers between $-2$ and $infty$ including $-2$, or we can write $y geq -2$.

The $x$-intercept is the point $x=4$.

The $y$-intercept is the point $y=-2$.

The function is not symmetric and does not have asymptotes.

The function is increasing for $x in [0, infty).$

The function has the minimum value of $-2$ for $x=0$.

The function is continious.

Result
3 of 3
The function is graphed and fully described as instructed.
Exercise 23
Step 1
1 of 7
a-

$(x+13)(x-7)=0$          (Write the equation)

$(x+13)=0$ or $(x-7)=0$          (Zero product propert)

$x=-13$ or $x=7$          (Solve for $x$)

Step 2
2 of 7
b-

$(2x+3)(3x-7)=0$          (Write the equation)

$(2x+3)=0$ or $(3x-7)=0$          (Zero product property)

$x=-dfrac {3}{2}$ or $x=dfrac {7}{3}$          (Solve fore $x$)

Step 3
3 of 7
c-

$x(x-3)=0$          (Write the equation)

$x=0$ or $(x-3)=0$          (Zero product property)

$x=0$ or $x=3$          (Solve fore $x$)

Step 4
4 of 7
d-

$x^2-5x=0$          (Write the equation)

$x(x-5)=0$          (Factor out $x$)

$x=0$ or $(x-5)=0$          (Zero product property)

$x=0$ or $x=5$          (Solve fore $x$)

Step 5
5 of 7
e-

$x^2-2x-35=0$          (Write the equation)

$(x-7)(x+5)=0$          (Factor the equation)

$x-7=0$ or $(x+5)=0$          (Zero product property)

$x=7$ or $x=-5$          (Solve fore $x$)

Step 6
6 of 7
f-

$3x^2+14x-5=0$          (Write the equation)

$(3x-1)(x+5)=0$          (Factor the equation)

$3x-1=0$ or $(x+5)=0$          (Zero product property)

$x=dfrac {1}{3}$ or $x=-5$          (Solve fore $x$)

Result
7 of 7
a-          $(x+13)(x-7)=0$ The solution is $x=-13$ or $x=7$

b-          $(2x+3)(3x-7)=0$ The solution is $x=-dfrac {3}{2}$ or $x=dfrac {7}{3}$

c-          $x(x-3)=0$ The solution is $x=0$ or $x=3$

d-          $x^2-5x=0$ The solution is $x=0$ or $x=5$

e-          $x^2-2x-35=0$ The solution is $x=7$ or $x=-5$

f-          $3x^2+14x-5=0$ The solution is $x=dfrac {1}{3}$ or $x=-5$

Exercise 24
Step 1
1 of 2
$f(x)=dfrac {1}{x-2}$          (Given)

a-          $f(2.5)=dfrac {1}{2.5-2}=dfrac {1}{0.5}=2$

b-          $f(1.75)=dfrac {1}{1.75-2}=dfrac {1}{0.25}=4$

c-          $f(2)=dfrac {1}{2-2}=dfrac {1}{0}$          (Division by 0 is undefined)

Result
2 of 2
a-          $f(2.5)=2$

b-          $f(1.75)=4$

c-          $f(2)=dfrac {1}{0}$          (Division by 0 is undefined)

Exercise 25
Step 1
1 of 8
$f(x)=-dfrac {2}{3}x+3$          Given

$g(x)=2x^2-5$          Given

Step 2
2 of 8
a-

$f(3)=-dfrac {2}{3}(3)+3=1$

Step 3
3 of 8
b-

$f(x)=-5$

$-5=-dfrac {2}{3}x+3$          (Substitute -5 for $f(x)$)

$dfrac {2}{3}x=8$          (Add $dfrac {2}{3}x$ and 5 to each side)

$x=8 times dfrac {3}{2}$          (Multiply each side by $dfrac {3}{2}$)

$$
x=12
$$

Step 4
4 of 8
c-

$g(-3)=2(-3)^2-5$

$g(-3)=18-5=13$

Step 5
5 of 8
d-

$g(x)=-7$

$-7=2x^2-5$

$2x^2=-2$

$x^2=-1$

$x=sqrt {-1}$

Since the radicand is less than 0. Then there is no real solution

Step 6
6 of 8
e-

$g(x)=8$

$2x^2-5=8$

$x^2=dfrac {13}{2}$

$x=sqrt {dfrac {13}{2}}$

Step 7
7 of 8
f-

$g(x)=9$

$2x^2-5=9$

$x^2=dfrac {14}{2}$

$x=sqrt {7}$

Result
8 of 8
a-          $f(3)=-dfrac {2}{3}(3)+3=1$

b-          For $f(x)=-5$,         $x=12$

c-          $g(-3)=2(-3)^2-5=13$

d-          For $g(x)=-7$,          $x=sqrt {-1}$          There is no real solution

e-          For $g(x)=8$,          $x=sqrt {dfrac {13}{2}}$

f-          For $g(x)=9$,          $x=sqrt {7}$

Exercise 26
Step 1
1 of 2
Assuming the function machine is $f(x)$

$f(-2)=-8$          (Given)

$f(-1)=-1$          (Given)

$f(0)=0$          (Given)

$f(3)=27$          (Given)

The machine function is:

$$
f(x)=x^3
$$

Result
2 of 2
The machine function is:          $f(x)=x^3$
Exercise 27
Step 1
1 of 3
$textbf{(a)}$ Given graph represents relation between cost of gas(in dollars) and volume of gas(in gallons).

It can be observed that both quantities are linearly related.

In the given volume of gas is an independent variable whereas cost of gas is a dependent variable

$textbf{(b)}$ Given graph represents relation between height of a person (in inches) and age of the person .

It can be observed that both quantities are non-linearly related.

In the given age of person is an independent variable whereas height of person is a dependent variable

$textbf{(c)}$ Given graph represents relation between levels of ozone concentration and number of years.

It can be observed that both quantities are exponentially(decaying) related.

In the given number of years is an independent variable whereas levels of ozone concentration is a dependent variable

$textbf{(d)}$ Given graph represents relation between number of classrooms and number of students.

It can be observed that there is a non continuous relation between both quantities .

In the given number of students is an independent variable whereas number of classrooms is a dependent variable

Step 2
2 of 3
$textbf{(e)}$ All the non negative integers can be possible inputs of the graph in part (d).

Similarly, all the non negative integers can be possible outputs of the graph in part (d).

As both number of classrooms and number of students can not be a negative quantity or a fraction

Result
3 of 3
(e) All the non negative integers can be possible input and outputs of the graph in part (d)
Exercise 28
Step 1
1 of 5
a.

Let us solve the following equation

$$
begin{align*}
3.9x-2.1 &= 11.2x+51.7 \
3.9x-11.2x &= 51.7+2.1 \
-7.3x &=53.8 \
x&= -frac{53.8}{7.3} = -7.3698.
end{align*}
$$

Therefore, the solution is
$$
color{#c34632} x=-7.3698.
$$

Step 2
2 of 5
b.

Let us solve the following equation

$$
begin{align*}
frac{1}{5} x-2 &= frac{13}{25}-0.7x \ \
frac{1}{5} x+0.7x &= frac{13}{25}+2 \ \
frac{2}{10} x+frac{7}{10} x &= frac{13}{25}+frac{50}{25} \ \
frac{9}{10} x &= frac{63}{25} \ \
x &= frac{63}{25} cdot frac{10}{9} = frac{7}{5} cdot frac{2}{1} = frac{14}{5} = 2.8.
end{align*}
$$

Therefore, the solution is
$$
color{#c34632} x=2.8.
$$

Step 3
3 of 5
c.

Let us solve the following equation

$$
begin{align*}
2+frac{2}{x} = 3 &implies frac{2}{x} = 3-2 \ &implies frac{2}{x} = 1 implies x = frac{2}{1} = 2.
end{align*}
$$

Therefore, the solution is
$$
color{#c34632} x=2.
$$

Step 4
4 of 5
d.

Let us solve the following equation

$$
begin{align*}
x+frac{3}{4} &= 4+2x \
x-2x &= 4- frac{3}{4} \
-x &= 4-0.75 \
-x &= 3.25 \
x &= -3.25.
end{align*}
$$

Therefore, the solution is
$$
color{#c34632} x=-3.25.
$$

Result
5 of 5
$$
begin{align*}
&text{a.} hspace{3mm} x=-7.3698 & &text{b.} hspace{3mm} x=2.8 \
&text{c.} hspace{3mm} x=2 & &text{d.} hspace{3mm} x=-3.25 \
end{align*}
$$
Exercise 29
Step 1
1 of 3
Let us consider the given function $$color{blue} f(x)=frac{1}{x-7}.$$
We can now make the table of the function.
begin{center}
begin{tabular}{ |c|c|c|c|c|c|c|c|c|c|c|c|c| }
hline
x & -5 & -3 & -1 & 0 & 1 & 4 & 6 & 6.5 & 7.5 & 8 & 12 \
hline
y & -0.083 & -0.1 & -0.125 & -0.143 & -0.166 & -0.16 & -1 & -2 & 2 & 1 & 0.2 \
hline
end{tabular}
end{center}
And now we can draw the graph. \

Exercise scan

Step 2
2 of 3
The table is not enough to sketch the graph fully and correctly. We have to comment that we have to be very careful when choosing the values for $x$ in the table. For some value of $x$, $x=7$, our function would not be defined. And if we didn’t choose values $6.5$ and $7.5$ we would not be able to predict the shape of our function completely. It can be helpful to determine the domain of the function and calculate the $x$-intercept and $y$-intercept first and then make the table. Evaluating the asymptotes before making the table can also be very helpful.

Now we can fully describe the graph.

The domain of the function are all real numbers except for $7$, we can write $x in (-infty,7) cup (7, infty)$.

The range of the function are all real numbers, except for $0$ so we can write $y in (-infty,0) cup (0, infty)$.

The $x$-intercept does not exist.

The $y$-intercept is the point $y=-0.143$.

The function is not symmetric.

The function has one vertical asymptote $x=7$ and one horizontal asymptote $y=0$.

The function is decreasing for $x in (-infty,7) cup (7, infty).$

The function does not have minimum or maximum points.

The function is not continuous.

Result
3 of 3
The graph is sketched and described as instructed.
Exercise 30
Step 1
1 of 7
a. \
Let us consider the given function $$ color{blue} f(x)=frac{1}{x-7}. $$
We can now make the table of the function.
begin{center}
begin{tabular}{ |c|c|c|c|c|c|c|c|c|c|c|c|c| }
hline
x & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 & 10 & 11 & 12 \
hline
y & -0.2 & -0.25 & -0.33 & -0.5 & -1 & / & 1 & 0.5 & 0.33 & 0.25 & 0.2 \
hline
end{tabular}
end{center}
The values for integers less that $7$ are negative, while the values for integers bigger than $7$ are the same just positive. In some way we can say the $y$-values are symmetric. \
Step 2
2 of 7
b.

Our function does not have value for $x=7$. The answer makes sense because we do not divide by $0$, and for the values $x=7$ that happens.

Step 3
3 of 7
c.

Now we plot all of the points that we have in our table so far.Exercise scan

Step 4
4 of 7
d. \
We can now make the additional table of the function.
begin{center}
begin{tabular}{ |c|c|c|c|c|c|c|c|c|c|c|c|c| }
hline
x & 6.5 & 6.7 & 6.9 & 6.99 & 7.01 & 7.1 & 7.3 & 7.5 \
hline
y & -2 & -3.33 & -10 & -100 & 100 & 10 & 3.33 & 2 \
hline
end{tabular}
end{center}
Step 5
5 of 7
e.

Let us add the new points to the graph and sketch the graph.Exercise scan

Step 6
6 of 7
f.

Now we can fully describe the graph.

The domain of the function are all real numbers except for $7$, we can write $x in (-infty,7) cup (7, infty)$.

The range of the function are all real numbers, except for $0$ so we can write $y in (-infty,0) cup (0, infty)$.

The $x$-intercept does not exist.

The $y$-intercept is the point $y=-0.143$.

The function is not symmetric.

The function has one vertical asymptote $x=7$ and one horizontal asymptote $y=0$.

The function is decreasing for $x in (-infty,7) cup (7, infty).$

The function does not have minimum or maximum points.

The function is not continuous.

Result
7 of 7
The exercise is solved as instructed.
Exercise 31
Step 1
1 of 5
a.

The graph of
$$
f(x)=frac{1}{x-h}
$$
has a vertical asymptote $x=h$ and a horizontal asymptote $y=0$.
As we graphed the function
$$
f(x)=frac{1}{x-7}
$$
we can write that our function has a vertical asymptote $x=7$ and a horizontal asymptote $y=0$.

We add these lines to our graph.

Exercise scan

Step 2
2 of 5
b. \
Now we choose a number between $-10$ and $10$. Let us choose $color{red} -3$. The new function is
$$color{red} f(x)=frac{1}{x-(-3)}=frac{1}{x+3}. $$
We can now make the table of the function.
begin{center}
begin{tabular}{ |c|c|c|c|c|c|c|c|c|c|c|c|c| }
hline
x & -8 & -5 & -4 & -3.5 & -2.5 & -2 & 0 & 2 & 5 \
hline
y & -0.2 & -0.5 & -1 & -2 & 2 & 1 & 0.33 & 0.2 & 0.125 \
hline
end{tabular}
end{center}
And now we can draw the graph.\

Exercise scan

Step 3
3 of 5
Now we can fully describe the graph.

The domain of the function are all real numbers except for $-3$, we can write $x in (-infty,-3) cup (-3, infty)$.

The range of the function are all real numbers, except for $0$ so we can write $y in (-infty,0) cup (0, infty)$.

The $x$-intercept does not exist.

The $y$-intercept is the point $y=0.33$.

The function is not symmetric.

The function has one vertical asymptote $x=-3$ and one horizontal asymptote $y=0$.

The function is decreasing for $x in (-infty,-3) cup (-3, infty).$

The function does not have minimum or maximum points.

The function is not continuous.

Step 4
4 of 5
c.

Analyzing the graph of each function we see that the shape of the graph is the same. It just translates left or right. Therefore, we can conclude that the function
$$
f(x)=frac{1}{x-h}
$$
has the graph of the same shape as function
$$
g(x)=frac{1}{x}
$$
just it is translated to the left by $h$ units if $h$ is negative or translated to the right by $h$ units if $h$ is positive.

We do not need to add any new attributes. All we have to do is slightly modify the existing ones.

Result
5 of 5
a. The vertical asymptote $x=h$ and horizontal asymptote $y=0$ have been added to the graph.

b. The function has been graphed for chosen $h=-3$.

c. We didn’t have to add any attributes, the graphs have the same shape, just translated left or right.

Exercise 32
Step 1
1 of 8
$$
f(x)=dfrac{1}{x+25}
$$
We are given the function:
Step 2
2 of 8
$$
x=-25
$$
a) The graph has a vertical asymptote (the denominator’s zero):
Step 3
3 of 8
$$
y=0
$$
and a horizontal asymptote (because the degree of the numerator is smaller than the degree of the numerator):
Step 4
4 of 8
Exercise scan
We use the graph of the function that we drew in Exercise 31:

$f_0(x)=dfrac{1}{x+2}$.

We horizontally translate the graph of $f_0$ 23 units to the left:

Step 5
5 of 8
Exercise scan
b) We use a graphing calculator to graph $f(x)$ (in a window [-4,4,1] by [-4,4,1]):
Step 6
6 of 8
This is not what we expected to see. The reason is the dimensions of the window we use.
Step 7
7 of 8
Exercise scan
c) We adjust the window to the dimensions [-35, -15,5] by [-12,12,2]:
Step 8
8 of 8
d) Our prediction was pretty close: the asymptotes, the shape of the graph. The graph drawn using the calculator is more precise in terms of drawing the important points.
Exercise 33
Step 1
1 of 3
(a)
All the functions of this type have $y-$intercept, but don’t have $x-$intercept. The function is discontinued at $x=h$, and they are decrease on the interval $(-infty,h)$ and the interval $(h,infty)$.

All the graphs of these functions have a **vertical asymptote** (the denominator’s zero):
$$textcolor{#c34632}{x=h}$$
and a **horizontal asymptote** (because the degree of the numerator is smaller than the degree of the numerator):
$$textcolor{#c34632}{y=0}$$

The **main difference** between these graphs is the distance from $y-$ axis.

Step 2
2 of 3
(b)
A variable is an entity which changes in a function’s equation, while a parameter is an entity that is used to connect or unify two or more variables,

A parameter is a variable that is held constant when the function is used. Varying a parameter given you a family of functions.

Step 3
3 of 3
(c)
Examples of families of functions:
$$f(x)=sqrt{x}+hhspace{1cm}textrm{where parent function is } f(x)=sqrt{x}$$
$$f(x)=sin(bx+c)hspace{1cm}textrm{where parent function is } f(x)=sin x$$
Exercise 34
Step 1
1 of 1
To apply this exercise, follow the following steps:
1. Construct a a Learning Log under supervision of your teacher.
2. Label each entry with a title and a date so you can refer to it or add to it later.
3. Explain how families of functions, parameters, and the descriptions of graphs are related. Title his entry “Families of Functions”.
Exercise 35
Step 1
1 of 3
a-          The domain of $g(x)$ is $(-2 leq x leq 4)$

b-          The range of $g(x)$ is $(-1 leq y leq 3)$

c-          Ricky is not correct. because the parabola of the function is a continuous line. i.e the range is all the real numbers between -1 and 3.

Step 2
2 of 3
d-

A graph of another function that is with the same domain and range of $g(x)$

Exercise scan

Result
3 of 3
a-          The domain of $g(x)$ is $(-2 leq x leq 4)$

b-          The range of $g(x)$ is $(-1 leq y leq 3)$

c-          Ricky is not correct. because the parabola of the function is a continuous line. i.e the range is all the real numbers between -1 and 3.

Exercise 36
Step 1
1 of 3
Let us consider
$$
color{#4257b2} (2x-1)(x+3)=4.
$$

Unfortunately, both George and Jeffrey are wrong. We can use the Zero Product Property only when the product equals zero. Therefore we multiply and get

$$
begin{align*}
(2x-1)(x+3) &=4 \
2x cdot x + 2x cdot 3 -1 cdot x-1cdot 3 &=4 \
2x^2+6x-x-3 &=4 \
2x^2 +5x -3 -4 &=0 \
2x^2 +5x -7 &=0.
end{align*}
$$

We have gotten the quadratic equation, therefore we can use the quadratic formula. We have

$$
a=2 hspace{12mm} b=5 hspace{12mm} c=-7.
$$

Now we use the formula
$$
x = frac{-b pm sqrt{b^2-4ac}}{2a}.
$$

Hence, we have

$$
begin{align*}
x &= frac{-5 pm sqrt{5^2-4 cdot 2 cdot (-7)}}{2 cdot 2} \
x &= frac{-5 pm sqrt{25+56}}{4} \
x &= frac{-5 pm sqrt{81}}{4} \
x &= frac{-5 pm 9}{4} \
x &= frac{-5 + 9}{4} hspace{3mm} text{or} hspace{3mm} frac{-5 – 9}{4} \
x &= frac{4}{4} hspace{3mm} text{or} hspace{3mm} frac{-14}{4} \
x &= 1 hspace{3mm} text{or} hspace{3mm} -3.5
end{align*}
$$

Therefore, the solutions are
$$
color{#c34632} x=1 hspace{3mm} text{color{default}or} hspace{3mm} x=-3.5
$$

Step 2
2 of 3
As instructed we check the solutions. First we substitute $x=1$ and get

$$
(2x-1)(x+3)= (2 cdot 1 -1)(1+3) = (2-1) cdot 4 = 1 cdot 4 = 4.
$$

Therefore, $x=1$ really is the solution. Now we check for $x=-3.5$. We substitute and get

$$
(2x-1)(x+3)= (2 cdot (-3.5) -1)(-3.5+3) = (-7-1) cdot (-0.5) = -8 cdot (-0.5) = 4.
$$

We can conclude that $x=-3.5$ is the correct solution too.

Result
3 of 3
$$
x=1 hspace{3mm} text{or} hspace{3mm} x=-3.5
$$
Exercise 37
Step 1
1 of 6
a-

$x=3y+6$          (Given)

$3y=x-6$          (Subtract 6 from each side)

$y=dfrac {x-6}{3}$          (y-form)

Step 2
2 of 6
b-

$x=5y-10$          (Given)

$5y=x+10$          (Add 10 to each side)

$y=dfrac {x+10}{5}$          (y-form)

Step 3
3 of 6
c-

$x=y^2$          (Given)

$y=sqrt {x}$          (y-form)

Step 4
4 of 6
d-

$x=2y^2-4$          (Given)

$2y^2=x+4$          (Add 4 to each side)

$y^2=dfrac {x+4}{2}$          (Divide each side by 2)

$y= sqrt {dfrac {x+4}{2}}$          (y-form)

Step 5
5 of 6
e-

$x=(y-5)^2$          (Given)

$y-5=sqrt {x}$          (Square root of each side)

$y=sqrt {x}+5$          (y-form)

Result
6 of 6
a-          $x=3y+6 qquad rightarrow qquad y=dfrac {x-6}{3}$

b-          $x=5y-10 qquad rightarrow qquad y=dfrac {x+10}{5}$

c-          $x=y^2 qquad rightarrow qquad y=sqrt {x}$

d-          $x=2y^2-4 qquad rightarrow qquad y= sqrt {dfrac {x+4}{2}}$

e-          $x=(y-5)^2 qquad rightarrow qquad y=sqrt {x}+5$

Exercise 38
Step 1
1 of 2
$f(x)=2x-7$          (Given)

a-          $f(0)=2(0)-7=0-7=-7$

b-          $f(x)=0$

$2x-7=0$

$2x=7$

$x=dfrac {7}{2}$

c-          The answer to part (a) tells us that the y-intercept for the function $f(x)=2x-7$ is the point $(0, -7)$

While the answer to part (b) tells us that the x-intercept for the function $f(x)=2x-7$ is the point $(dfrac {7}{2}, 0)$

Result
2 of 2
a-          $f(0)=2(0)-7=0-7=-7$

b-          $f(x)=0 qquad rightarrow qquad x=dfrac {7}{2}$

c-          Part (a) tells us that the y-intercept is the point $(0, -7)$

While part (b) tells us that the x-intercept is the point $left(dfrac {7}{2}, 0 right)$

Exercise 39
Step 1
1 of 3
Assuming the length of the piece that Jill cuts of is $x$ and the remaining piece is $y$, the equation that represents the situation is:\
$y=30-x$\
\
The below table represents the situation.\
begin{center}
begin{tabular}{|l|l|}
hline
$x$ & $y=30-x$ \ hline
5 & 25 \ hline
10 & 20 \ hline
15 & 15 \ hline
20 & 10 \ hline
25 & 5 \ hline
end{tabular}
end{center}
Step 2
2 of 3
The graph of the situation.Exercise scan
Result
3 of 3
The equation that represents the situation is $y=30-x$
Exercise 40
Step 1
1 of 3
Let’s note:

$t$=the time of the day

$f(t)$=the number of people in the school’s campus as a function of the time of the day $t$

Step 2
2 of 3
begin{center}
begin{tabular}{|| c| c||}
hline
t & f(t) \ [0.5ex]
hline
1 & 1 \
hline
2 & 1 \
hline
3 & 1 \
hline
4 & 1 \
hline
5 & 2 \
hline
6 & 3 \
hline
7 & 52 \
hline
8 & 404 \
hline
9 & 408 \
hline
10 & 407 \
hline
11 & 405 \
hline
12 & 400 \
hline
13 & 285 \
hline
14 & 299 \
hline
15 & 400 \
hline
16 & 380 \
hline
17 & 370 \
hline
18 & 201 \
hline
19 & 83 \
hline
20 & 17 \
hline
21 & 8 \
hline
22 & 4 \
hline
23 & 1 \
hline
24 & 1 \[1ex]
hline
end{tabular}
end{center}
We collect data and place it in a table:
Step 3
3 of 3
Exercise scan
We plot the points and sketch the graph:
Exercise 41
Step 1
1 of 2
The error is multiplying only one side of the equation by $x$ and ignoring the other.

$x cdot dfrac {5}{x}=x-4$          (The error)

The correct solution is:

$x cdot dfrac {5}{x}=x cdot (x-4)$          (Multiplying each side by $x$)

$5=x^2-4x$          (Distributive property)

$x^2-4x-5=0$

$(x-5)(x+1)=0$          (Factoring the polynomial)

$x-5=0$ or $x+1=0$

$x=5$ or $x=-1$

Checking the solutions

For $x=5$

$x^2-4x-5=0$

$5^2-4(5)-5$          (Substituting 5 for $x$)

$25-20-5=0$          $checkmark$

For $x=-1$

$(-1)^2-4(-1)-5=0$

$1+4-5=0$          (Substituting -1 for $x$)

$0=0$          $checkmark$

Result
2 of 2
The error is multiplying only one side of the equation by $x$ and ignoring the other.

The correct solution is:          $x=5$ or $x=-1$

Exercise 42
Step 1
1 of 3
Let us consider the given function $$color{blue} f(x)=frac{2}{x}.$$
We can now make the table of the function.
begin{center}
begin{tabular}{ |c|c|c|c|c|c|c|c|c|c|c|c|c| }
hline
x & -4 & -3 & -2 & -1 & 0 & 1 & 2 & 3 & 4 \
hline
y & -0.5 & -0.66 & -1 & -2 & / & 2 & 1 & 0.66 & 0.5 \
hline
end{tabular}
end{center}
And now we can draw the graph.
\

Exercise scan

Step 2
2 of 3
Now we can fully describe the graph.

The domain of the function are all real numbers except for $0$, we can write $x in (-infty,0) cup (0, infty)$.

The range of the function are all real numbers, except for $0$ so we can write $y in (-infty,0) cup (0, infty)$.

The $x$-intercept and $y$-intercept do not exist.

The function is symmetric.

The function has one vertical asymptote $x=0$ and one horizontal asymptote $y=0$.

The function is decreasing for $x in (-infty,0) cup (0, infty).$

The function does not have minimum or maximum points.

The function is not continuous.

Result
3 of 3
The graph is sketched and described as instructed.
Exercise 43
Step 1
1 of 3
a-

Decreasing temperature could be represented by the following graph.Exercise scan

Step 2
2 of 3
b-

The graph should have an asymptote represents the room temperature that pizza temperature could not go down it.

Result
3 of 3
The graph should have an asymptote represents the room temperature
Exercise 44
Step 1
1 of 3
a-

$dfrac {6}{x}=x-1$          (Write the equation)

$6=x^2-x$          (Multiplying each side by $x$)

$x^2-x-6=0$          (Subtracting 6 from each side)

$(x-3)(x+2)=0$          (Factoring)
$x-3=0$ or $x+2=0$          (Zero product property)

$x=3$ or $x=-2$          (Solving for $x$)

Checking the solution

For $x=3$

$dfrac {6}{3}=3-1$

$2=2$          checkmark

For $x=-2$

$dfrac {6}{-2}=-2-1$

$-3=-3$          checkmark

Step 2
2 of 3
b-

$dfrac {9}{x}=x$          (Write the equation)

$9=x^2$          (Multiplying each side by $x$)

$x=sqrt 9$

$x=3$          (Solving for $x$)

Checking the solution

For $x=3$

$dfrac {9}{3}=3$

$3=3$          checkmark

Result
3 of 3
a-          $x=3$ or $x=-2$

b-          $x=3$

Exercise 45
Step 1
1 of 2
The machine function is:

$f(x)=x^2+2x+1$          (Given)

If the output is 1, then $f(x)=1$

$1=x^2+2x+1$          (Substitut 1 for $f(x)$)

$x^2+2x=0$          (Subtract 1 from each side)

$x(x+2)=0$          (Factor out $x$

$x=0$ or $(x+2=0)$          (Zero product property)

$x=0$ or $x=-2$          (Solve for $x$)

The number that could have dropped in the machine function are 0, -2

Result
2 of 2
The number that could have dropped in the machine function are 0, -2
Exercise 46
Step 1
1 of 8
The value that allows us to find the y-intercept is: $x=0$
Step 2
2 of 8
a-          $y=3x+6$          (Write the equation)

For y-intercept, Substitute $x=0$

$y=3(0)+6=6$

y-intercept is $(0, 6)$

Step 3
3 of 8
b-          $x=5y-10$          (Write the equation)

$y=dfrac {x+10}{5}$          (Write the equation in the term of $y$)

For y-intercept, Substitute $x=0$

$y=dfrac {0+10}{5}=2$

y-intercept is $(0, 2)$

Step 4
4 of 8
c-          $y=x^2$          (Write the equation)

For y-intercept, Substitute $x=0$

$y=(0)^2=0$

y-intercept is $(0, 0)$

Step 5
5 of 8
d-          $y=2x^2-4$          (Write the equation)

For y-intercept, Substitute $x=0$

$y=2(0)^2-4=-4$

y-intercept is $(0, -4)$

Step 6
6 of 8
e-          $y=(x-5)^2$          (Write the equation)

For y-intercept, Substitute $x=0$

$y=(0-5)^2=25$

y-intercept is $(0, 25)$

Step 7
7 of 8
f-          $y=3x^3-2x^2+13$          (Write the equation)

For y-intercept, Substitute $x=0$

$y=3(0)^3-2(0)^2+13=13$

y-intercept is $(0, 13)$

Result
8 of 8
The value that allows us to find the y-intercept is: $x=0$

a-          y-intercept is $(0, 6)$

b-          y-intercept is $(0, 2)$

c-          y-intercept is $(0, 0)$

d-          y-intercept is $(0, -4)$

e-          y-intercept is $(0, 25)$

e-          y-intercept is $(0, 13)$

Exercise 47
Step 1
1 of 5
a.

Let us solve the given equation
$$
color{#4257b2} x^2+7x-8=0.
$$

This one can be solved by factoring and applying the Zero Productivity Rule. We get

$$
begin{align*}
x^2+7x-8 &=0 \
x^2 +8x-x-8 &=0 \
x cdot (x+8) -(x+8) &=0 \
(x+8)(x-1) &=0.
end{align*}
$$

Now we apply the Zero Product Rule which yields

$$
begin{align*}
(x+8)(x-1) =0 \
x+8 = 0 hspace{3mm} text{or} hspace{3mm} x-1=0 \
x=-8 hspace{3mm} text{or} hspace{3mm}x=1.
end{align*}
$$

Therefore, the solutions are
$$
color{#c34632} x=1 hspace{3mm} text{color{default}or} hspace{3mm} x=-8.
$$

Step 2
2 of 5
b.

Let us solve the given equation
$$
color{#4257b2} (x+2)^2=49.
$$

This one can be solved by factoring and applying the Zero Productivity Rule. We get

$$
begin{align*}
(x+2)^2 &=49 \
(x+2)^2-49 &=0 \
(x+2)^2-7^2 &=0.
end{align*}
$$

Using the difference of two squares identity gives us

$$
begin{align*}
(x+2)^2-7^2 &=0 \
(x+2-7)(x+2+7) &=0 \
(x-5)(x+9) &=0 \
end{align*}
$$

Now we apply the Zero Product Rule which yields

$$
begin{align*}
(x-5)(x+9) =0 \
x-5 = 0 hspace{3mm} text{or} hspace{3mm} x+9=0 \
x=5 hspace{3mm} text{or} hspace{3mm} x=-9.
end{align*}
$$

Therefore, the solutions are
$$
color{#c34632} x=5 hspace{3mm} text{color{default}or} hspace{3mm} x=-9
$$

Step 3
3 of 5
c.

Let us solve the given equation
$$
color{#4257b2} 5x^2-x-7=0.
$$

This time we can use the quadratic formula
$$
x = frac{-b pm sqrt{b^2-4ac}}{2a}.
$$
We have

$$
a=5 hspace{12mm} b=-1 hspace{12mm} c=-7.
$$

Hence, we have

$$
begin{align*}
x &= frac{-(-1) pm sqrt{(-1)^2-4 cdot 5 cdot (-7)}}{2 cdot 5} \
x &= frac{1 pm sqrt{1+140}}{10} \
x &= frac{1 pm sqrt{141}}{10} \
x &= frac{1 + sqrt{141}}{10} hspace{3mm} text{or} hspace{3mm} frac{1 – sqrt{141}}{10}.
end{align*}
$$

Therefore, the solutions are
$$
color{#c34632} x=frac{1 + sqrt{141}}{10} hspace{3mm} text{color{default}or} hspace{3mm} x=frac{1 – sqrt{141}}{10}
$$

Step 4
4 of 5
d.

Let us solve the given equation
$$
color{#4257b2} x^2+4x=-1.
$$

We rewrite it
$$
x^2+4x+1=0
$$

and now we can use the quadratic formula
$$
x = frac{-b pm sqrt{b^2-4ac}}{2a}.
$$
We have

$$
a=1 hspace{12mm} b=4 hspace{12mm} c=1.
$$

Hence, we have

$$
begin{align*}
x &= frac{-4 pm sqrt{4^2-4 cdot 1 cdot 1}}{2 cdot 1} \
x &= frac{-4 pm sqrt{16-4}}{2} \
x &= frac{-4 pm sqrt{12}}{2} \
x &= frac{-4 pm sqrt{4 cdot 3}}{2} \
x &= frac{-4 pm 2sqrt{3}}{2} \
x &= frac{2 cdot (-2 pm sqrt{3})}{2} \
x &= -2 pm sqrt{3} \
x &= -2 + sqrt{3} hspace{3mm} text{or} hspace{3mm} -2 – sqrt{3}.
end{align*}
$$

Therefore, the solutions are
$$
color{#c34632} x= -2 + sqrt{3} hspace{3mm} text{color{default}or} hspace{3mm} x= -2 – sqrt{3}.
$$

Result
5 of 5
$$
begin{align*}
&text{a.} hspace{3mm} x=1 hspace{3mm} text{or} hspace{3mm} x=-8 \
&text{b.} hspace{3mm} x=5 hspace{3mm} text{or} hspace{3mm} x=-9 \
&text{c.} hspace{3mm} x=frac{1 + sqrt{141}}{10} hspace{3mm} text{or} hspace{3mm} x=frac{1 – sqrt{141}}{10} \
&text{d.} hspace{3mm} x= -2 + sqrt{3} hspace{3mm} text{color{default}or} hspace{3mm} x= -2 – sqrt{3} \
end{align*}
$$
Exercise 48
Step 1
1 of 4
Let us graph the line $$color{blue} y=3x+3.$$
We can now make the table of the function.
begin{center}
begin{tabular}{ |c|c|c|c| }
hline
x & -1 & 0 \
hline
y & 0 & 3 \
hline
end{tabular}
end{center}
And now we can draw the graph.\

Exercise scan

Step 2
2 of 4
a.

Let us sketch the line that is perpendicular to the line
$$
y=3x+3
$$
and passes through the point $(-3,2)$.

Exercise scan

Step 3
3 of 4
b.

Let us write the equation of the perpendicular line to the line
$$
y=3x+3.
$$
We need to find the equation

$$
color{#4257b2} y=k cdot x+n.
$$

We can find the coefficient $k$ using the fact that the two lines are perpendicular. We have

$$
k=-frac{1}{3}.
$$

In order to find $n$ we use the fact that our wanted line passes through $(-3, 2)$. We substitute $k=-1/3$, $x=-3$ and $y=2$ and get

$$
2=-frac{1}{3} cdot (-3) +n implies 2=1+n implies n=2-1=1.
$$

Therefore, the equation of the perpendicular line to the line $y=3x+3$ is

$$
color{#c34632} y=-frac{1}{3}x+1.
$$

Result
4 of 4
a. We graphed the line $y=3x+3$ and the line that is perpendicular to it and passes through $(-3, 2)$.

b. The equation of the perpendicular line to $y=3x+3$ is
$$
y=-frac{1}{3}x+1.
$$

Exercise 49
Step 1
1 of 5
Let us consider the given functions

$$
color{#4257b2} f_1(x) = x-2 hspace{4mm} text{color{default} and} hspace{4mm} g_1(x)=2x+3.
$$

First we try to predict the shape of the new graph of the sum of the functions. Since we are summing two linear functions we predict our new function will be linear again.

$$
p(x)=f_1(x) + g_1(x) = x-2+2x+3 = 3x+1.
$$

As we predicted the function is linear.
Let us sketch the given functions along with the new function. We see the graph below.

Exercise scan

Step 2
2 of 5
First we try to predict the shape of the new graph of the difference of the functions. Since we are subtracting two linear functions we predict our new function will be linear again.

$$
q(x)=f_1(x) – g_1(x) = x-2-(2x+3) = x-2-2x-3 = -x-5.
$$

As we predicted the function is linear.
Let us sketch the given functions along with the new function. We see the graph below.

Exercise scan

Step 3
3 of 5
First we try to predict the shape of the new graph of the product of the functions. Since we are multiplying two linear functions we predict our new function will be a quadratic function.

$$
r(x)=f_1(x) cdot g_1(x) = (x-2)(2x+3) = 2x^2 +3x-4x-6 = 2x^2-x-6.
$$

As we predicted the function is quadratic. Let us sketch the given functions along with the new function. We see the graph below.

Exercise scan

Step 4
4 of 5
Let us divide the two give functions.

$$
t(x)=frac{f_1(x)}{ g_1(x)} = frac{x-2}{2x+3}.
$$

Let us sketch the given functions along with the new function. We see the graph below.

Exercise scan

Result
5 of 5
The sum, difference, product and quotient of the two functions are graphed.
Exercise 50
Step 1
1 of 5
Let us consider the given functions

$$
color{#4257b2} f_1(x) = x-2 hspace{4mm} text{color{default} and} hspace{4mm} g_1(x)=2x+3.
$$

First we try to predict the shape of the new graph of the sum of the functions. Since we are summing two linear functions we predict our new function will be linear again.

$$
p(x)=f_1(x) + g_1(x) = x-2+2x+3 = 3x+1.
$$

As we predicted the function is linear. Let us sketch the given functions along with the new function. We see the graph below.

Exercise scan

Step 2
2 of 5
Now we can fully describe the graph.

The sum function is linear. The domain of the function are all real numbers. Same goes for the range, it includes all real numbers.

The $x$-intercept is $x=-1/3$, while the $y$-intercept is $y=0$.

The function is increasing for $x in (-infty, infty)$. Hence, our function does not have minimum or maximum points.

Also, we can now comment all the possible cases when summing two linear functions. One possibility is the one we have here, we can get a linear function. But if the leading coefficients of two functions we are summing are opposite numbers, the result would be a constant function. Those are the only two options.

Step 3
3 of 5
Let us consider the given functions

$$
color{#4257b2} f_1(x) = x-2 hspace{4mm} text{color{default} and} hspace{4mm} g_1(x)=2x+3.
$$

First we try to predict the shape of the new graph of the difference of the functions. Since we are subtracting two linear functions we predict our new function will be linear again.

$$
q(x)=f_1(x) – g_1(x) = x-2-(2x+3) = x-2-2x-3=-x-5.
$$

As we predicted the function is linear. Let us sketch the given functions along with the new function. We see the graph below.

Exercise scan

Step 4
4 of 5
Now we can fully describe the graph.

The sum function is linear. The domain of the function are all real numbers. Same goes for the range, it includes all real numbers.

The $x$-intercept is $x=-5$, while the $y$-intercept is $y=-5$.

The function is increasing for $x in (-infty, infty)$. Hence, our function does not have minimum or maximum points.

Also, we can now comment all the possible cases when subtracting two linear functions. One possibility is the one we have here, we can get a linear function. But if the leading coefficients of two functions we are subtracting are the same numbers, the result would be a constant function. Those are the only two options.

Result
5 of 5
The sum and difference of two linear functions can only be a linear or a constant function.
Exercise 51
Step 1
1 of 3
Let us consider the given functions

$$
color{#4257b2} f_1(x) = x-2 hspace{4mm} text{color{default} and} hspace{4mm} g_1(x)=2x+3.
$$

First we try to predict the shape of the new graph of the product of the functions. Since we are multiplying two linear functions we predict our new function will be a quadratic function.

$$
r(x)=f_1(x) cdot g_1(x) = (x-2)(2x+3) = 2x^2 +3x-4x-6 = 2x^2-x-6.
$$

As we predicted the function is quadratic. Let us sketch the given functions along with the new function. We see the graph below.

Exercise scan

Step 2
2 of 3
Now we can fully describe the graph.

The product function is quadratic. The parabola opens upward. The domain of the function are all real numbers. The range is $[-6.125, infty)$.

The $x$-intercept is $x=-6$, while the $y$-intercept are $y=-1.5$ and $y=2$.

The function is decreasing for $x in (-infty, 0.25)$ and decreasing for $x in (0.25, infty)$. Hence, our function has a minimum point $(0.25, -6.125)$.

Also, we can now comment the product of two linear functions can be a quadratic function. But if one of the linear functions is a constant vertical function then the product will be a linear function. Therefore, the product of two linear functions is a quadratic function, with the exception when one of the functions is a constant vertical function then the product is a linear function.

Result
3 of 3
The product of two linear functions is a quadratic function, with the exception when one of the functions is a constant vertical function then the product is a linear function.
Exercise 52
Step 1
1 of 3
Let us consider the given functions

$$
color{#4257b2} f_1(x) = x-2 hspace{4mm} text{color{default} and} hspace{4mm} g_1(x)=2x+3.
$$

Let us divide the two give functions.

$$
t(x)=frac{f_1(x)}{ g_1(x)} = frac{x-2}{2x+3}.
$$

Let us sketch the given functions along with the new function. We see the graph below.

Exercise scan

Step 2
2 of 3
Now we can fully describe the graph.

The quotient function has the shape of hyperbola. The domain of the function are all real numbers except for $-3/2$, therefore the domain is
$$
(-infty,-frac{3}{2}) cup (-frac{3}{2}, infty).
$$
The range are all real numbers except for $1/2$, therefore

$$
(-infty,frac{1}{2}) cup (frac{1}{2}, infty).
$$

The $x$-intercept is $x=2$, while the $y$-intercept is $y=-2/3$.

The function is increasing for $x in (-infty,-frac{3}{2}) cup (-frac{3}{2}, infty)$. Hence, our function does not have a minimum or maximum point.

Also, we can now comment the asymptotes of the quotient function. This function has one vertical and one horizontal asymptotes. The vertical asymptote is
$$
x=-frac{3}{2}
$$
and the horizontal asymptote is
$$
y=frac{1}{2}.
$$

Result
3 of 3
The quotient function is graphed and the function has one vertical and one horizontal asymptote.
Exercise 53
Step 1
1 of 3
a.

Let us consider the given functions

$$
color{#4257b2} f_1(x) = x-2 hspace{4mm} text{color{default} and} hspace{4mm} g_1(x)=2x+3.
$$

First, we evaluate the sum function. We have

$$
f_1(x) + g_1(x) = x-2+2x+3 = 3x+1.
$$

The sum function $text{color{#c34632} is}$ a polynomial function. It’s degree is $color{#c34632}1$.

Now we evaluate the difference function. We have

$$
f_1(x) – g_1(x) = x-2-(2x+3) = x-2-2x-3 = -x-5.
$$

The difference function $text{color{#c34632} is}$ a polynomial function. It’s degree is $color{#c34632} 1$.

Next, we consider the product function. We multiply and get

$$
f_1(x) cdot g_1(x) = (x-2)(2x+3) = 2x^2 +3x-4x-6 = 2x^2-x-6.
$$

The product function $text{color{#c34632} is}$ a polynomial function. It’s degree is $color{#c34632} 2$.

Finally we consider the quotient function. We have

$$
frac{f_1(x)}{ g_1(x)} = frac{x-2}{2x+3}.
$$

The quotient function $text{color{#c34632} is not}$ a polynomial function because the variable is in the denominator.

Step 2
2 of 3
b.

Let us discuss if the results from part (a) be generalized.

The sum function of two linear functions can be a linear function or a constant form of linear function. Therefore, the function is always linear, hence it is always a polynomial function, but the degree of the polynomial is not always the same. If the leading coefficients of the functions we are summing are opposite numbers then the degree is $0$, otherwise the degree is $1$.

The difference function of two linear functions can be a linear function or a constant form of linear function. Therefore, the function is always linear, hence it is always a polynomial function, but the degree of the polynomial is not always the same. If the leading coefficients of the functions we are summing are the same numbers then the degree is $0$, otherwise the degree is $1$.

The product function of two linear functions can be a quadratic function or a linear function. Therefore, the function is always a polynomial function, but the degree of the polynomial is not always the same. If none of the functions we are multiplying is not a constant vertical function then the degree of the polynomial is $2$, otherwise the degree is $1$.

The quotient function of two linear functions can be a polynomial function only if the function in the denominator is a constant vertical function. In that case the degree of the polynomial is $1$. But if the variable is in the denominator, the quotient function is not a polynomial function.

Result
3 of 3
a. In the chosen example the sum, difference and product functions are polynomial functions and the quotient function is not a polynomial function.

b. We generalized our conclusions.

Exercise 54
Step 1
1 of 4
a.

One-variable polynomials are a closed set under addition or subtraction. If we add or subtract any two polynomials that both have the same variable the result will always be a polynomial. The degree of the polynomials might vary, but it will be a polynomial.

Step 2
2 of 4
b.

One-variable polynomials are a closed set under multiplication. If we multiply any two polynomials that both have the same variable the result will always be a polynomial. The degree of the polynomials might vary, but it will be a polynomial.

Step 3
3 of 4
c.

One-variable polynomials are not closed under division. As we have seen in previous exercises dividing two polynomials might not always be a polynomial. If there is a variable in the denominator the function is not a polynomial function. The examples are given in the exercise $49$ and $53$.

Result
4 of 4
a. One-variable polynomials are a closed set under multiplication.

b. One-variable polynomials are a closed set under addition or subtraction.

c. One-variable polynomials are not a closed set under division.

Exercise 55
Step 1
1 of 7
Let us consider the given functions

$$
color{#4257b2} p(x) = x^3-3x-1 hspace{4mm} text{color{default} and} hspace{4mm} q(x)=x-1.
$$

We graph the function
$$
color{#c34632} p(x) = x^3-3x-1
$$
as seen below. Now we can describe the graph.

The function is polynomial function. The domain of the function are all real numbers. Same goes for the range, it includes all real numbers.

The $x$-intercept are $x=-1.532$, $x=-0.347$ and $x=1.879$, while the $y$-intercept is $y=-1$.

The function is increasing for $x in (-infty, -1) cup (1,infty)$ and the function is decreasing for $x in (-1,1)$. Hence, our function has a local maximum point $(-1,1)$ and a local minimum point $(1,-3)$.

The function is not symmetric, but it is continuous.

Exercise scan

Step 2
2 of 7
Now we graph the function
$$
color{#c34632} q(x) = x-1
$$
as seen below. We can describe the graph.

The function is linear and polynomial function. The domain of the function are all real numbers. Same goes for the range, it includes all real numbers.

The $x$-intercept are $x=1$, while the $y$-intercept is $y=-1$.

The function is increasing for $x in (-infty, infty)$. Hence, our function does not have minimum or maximum points.

The function is not symmetrical, but it is continuous.

Exercise scan

Step 3
3 of 7
a.

Let us consider the given functions

$$
color{#4257b2} p(x) = x^3-3x-1 hspace{4mm} text{color{default} and} hspace{4mm} q(x)=x-1.
$$

Now we evaluate the sum function.

$$
g(x)=p(x) + q(x) = x^3-3x-1+x-1 =color{#c34632} x^3-2x-2.
$$

Let us sketch the given functions along with the sum function. We see the graph below.

Now we can describe the graph.

The function is polynomial function. The domain of the function are all real numbers. Same goes for the range, it includes all real numbers.

The $x$-intercept are $x=1.769$, while the $y$-intercept is $y=-2$.

The function is increasing for $x in (-infty, -0.8) cup (0.8,infty)$ and the function is decreasing for $x in (-0.8,0.8)$. Hence, our function has a local maximum point $(-0.8,-0.9)$ and a local minimum point $(0.8,-3.1)$.

The function is not symmetric, but it is continuous.

Exercise scan

Step 4
4 of 7
b.

Let us consider the given functions

$$
color{#4257b2} p(x) = x^3-3x-1 hspace{4mm} text{color{default} and} hspace{4mm} q(x)=x-1.
$$

Now we evaluate the difference function.

$$
f(x)=p(x) – q(x) = x^3-3x-1-(x-1) =x^3-3x-1-x+1 =color{#c34632} x^3-4x.
$$

Let us sketch the given functions along with the difference function. We see the graph below.

Now we can describe the graph.

The function is polynomial function. The domain of the function are all real numbers. Same goes for the range, it includes all real numbers.

The $x$-intercept are $x=-2$, $x=0$ and $x=2$, while the $y$-intercept is $y=0$.

The function is increasing for $x in (-infty, -1.15) cup (1.15, infty)$ and the function is decreasing for $x in (-1.15,1.15)$. Hence, our function has a local maximum point $(-1.15, 3.08)$ and a local minimum point $(0.8, -3.08)$.

The function is symmetric and it is continuous.

Exercise scan

Step 5
5 of 7
c.

Let us consider the given functions

$$
color{#4257b2} p(x) = x^3-3x-1 hspace{4mm} text{color{default} and} hspace{4mm} q(x)=x-1.
$$

Now we multiply the given functions and get

$$
begin{align*}
h(x) &=p(x) cdot q(x) = (x^3-3x-1)(x-1) \ &=x^4-x^3-3x^2+3x-x+1 \ &=color{#c34632} x^4-x^3-4x^2+2x+1.
end{align*}
$$

Let us sketch the given functions along with the product function. We see the graph below.

Now we can describe the graph.

The function is polynomial function. The domain of the function are all real numbers. And the range is $[-2.04, infty)$.

The $x$-intercept are $x=-1.53$, $x=-0.35$, $x=1$ and $x=1.88$, while the $y$-intercept is $y=1$.

The function is increasing for $x in (-1.08, 0.31) cup (1.52, infty)$ and the function is decreasing for $x in (-infty, -1.08) cup (0.31, 1.52)$. Hence, our function has a local maximum point $(0.31, 1.31)$ and two local minimum points $(-1.08, -2.04)$ and $(1.52, -1.07)$.

The function is not symmetric, but it is continuous.

Exercise scan

Step 6
6 of 7
d.

Let us consider the given functions

$$
color{#4257b2} p(x) = x^3-3x-1 hspace{4mm} text{color{default} and} hspace{4mm} q(x)=x-1.
$$

Now we evaluate the quotient function.

$$
r(x)=frac{p(x)}{q(x)}=color{#c34632} frac{x^3-3x-1}{x-1}.
$$

Let us sketch the given functions along with the quotient function. We see the graph below.

Now we can describe the graph.

The domain of the function are all real numbers except $1$, hence the domain is $(-infty, 1) cup (1, infty)$. The range includes all real numbers.

The $x$-intercept are $x=-1.53$, $x=-0.35$ and $x=1.88$, while the $y$-intercept is $y=1$.

The function is increasing for $x in (-0.91, 1) cup (1, infty)$ and the function is decreasing for $x in (-infty,-0.91)$. Hence, our function has a local minimum point $(-0.91, -0.51)$.

The function is not symmetric and it is not continuous.

The quotient function has a vertical asymptote $x=1$.

Exercise scan

Result
7 of 7
The given functions and the sum, difference, product and quotient functions are all graphed and described.
Exercise 56
Step 1
1 of 3
$f(x)=3x^2-5$          (Given)

$g(x)=sqrt {x-5}+2$          (Given)

Step 2
2 of 3
a-          $f(5)=3(5)^2-5=75-5=70$

b-          $g(5)=sqrt {5-5}+2=0+2=2$

c-          $f(4)=3(4)^2-5=48-5=43$

d-          $g(4)=sqrt {4-5}+2=sqrt {-1}+2$          (The radicand is less than 0 so there is no real solution)

e-          $f(x)+g(x)=3x^2-5+sqrt {x-5}+2=3x^2+sqrt {x-5}-3$

f-          $g(x)-f(x)=sqrt {x-5}+2-(3x^2-5)=-3x^2+sqrt {x-5}+7$

g-          The domain of $f(x)$ is $(-infty<x<infty)$

h-          The domain of $g(x)$ is $(5 leq x)$

i-          The domain of the function $g(x)$ is more restrictive than the domain of $f(x)$ because $g(x)$ is a radical function. the radicand is $(x-5)$ that can't be negative value.

Result
3 of 3
a- $f(5)=70$          b- $g(5)=2$          c- $f(4)=43$

d- $g(4)=sqrt {-1}+2$          (The radicand is less than 0 so there is no real solution)

e- $f(x)+g(x)=3x^2+sqrt {x-5}-3$          f-          $g(x)-f(x)=-3x^2+sqrt {x-5}+7$

g- The domain of $f(x)$ is $(-infty<x<infty)$          h- The domain of $g(x)$ is $(5 leq x)$

i- The domain of the function $g(x)$ is more restrictive than the domain of $f(x)$ because $g(x)$ is a radical function. the radicand is $(x-5)$ that can't be negative value.

Exercise 57
Step 1
1 of 3
a.

The given function
$$
y=3x^2+2x^2+x = 5x^2+x
$$
is a polynomial function.

b. The given function
$$
y=(x-2)^2(x-2)^2 = (x-2)^4 = x^4-8x^3+24x^2-32x+16
$$
is a polynomial function.

c. The given function
$$
y=x^2+2^x
$$
is not a polynomial function because the variable is in the exponent.

d.

The given function
$$
y=3x-1
$$
is a polynomial function.

e.

The given function
$$
y=(x-2)^2-1 = x^2-4x+4-1=x^2-4x+3
$$
is a polynomial function.

Step 2
2 of 3
f.

The given function
$$
y^2=(x-2)^2-1 implies y= sqrt{(x-2)^2-1}
$$
is not a polynomial function because the variable is inside the radical.

g. The given function
$$
y=frac{1}{x^2}+frac{1}{x}+frac{1}{2}
$$
is not a polynomial function because the variable is in the denominator.

h. The given function
$$
y=frac{1}{2}x+frac{1}{3}
$$
is a polynomial function.

i.

The given function
$$
y=x
$$
is a polynomial function.

j.

The given function
$$
y=-7
$$
is a polynomial function.

Result
3 of 3
a. Yes.      b. Yes.      c. No      d. Yes.      e. Yes.

f. No.      g. No.      h. Yes.      i. Yes.      j. Yes.

Exercise 58
Step 1
1 of 7
The initial height $=2$ feet.

The weekly growth $=3$ in $=dfrac {3}{12}=dfrac {1}{4}$ feet.

Assuming $x$ is the days passed from planting the tree. and $y$ is the total height of the tree after $x$ days.

The weeks passe $w=dfrac {x}{7}$

Step 2
2 of 7
a-

The equation that represents this relation is:

$y=dfrac {1}{4}w+2$

$y=dfrac {1}{4} times dfrac {x}{7}+2$

$y=dfrac {x}{28}+2$

Step 3
3 of 7
The below is the data table for the first 4 weeks.\
\
begin{center}
begin{tabular}{|c|c|}
hline
begin{tabular}[c]{@{}c@{}}Days\ $x$end{tabular} & begin{tabular}[c]{@{}c@{}}Height of the tree\ $y$ feetend{tabular} \ hline
0 & 2 \ hline
7 & 2.25 \ hline
14 & 2.5 \ hline
21 & 2.75 \ hline
28 & 3 \ hline
end{tabular}
end{center}
Step 4
4 of 7
Exercise scan
Step 5
5 of 7
b-

If the tree is 6 feet tall, then $y=6$

$6=dfrac {x}{28}+2$          (Substituting 6 for $y$)

$dfrac {x}{28}=4$          (Subtracting 2 from each side)

$x=112$          (Solve for $x$)

$w=dfrac {x}{7}=dfrac {112}{7}=16$ weeks

The tree will be 6 feet tall after 112 days (16 weeks)

Step 6
6 of 7
c-

The possible inputs of the graph is $(x geq 0)$

The possible outputs of the graph is $(y geq 2)$

Result
7 of 7
a-          The equation that represents this relation is: $y=dfrac {x}{28}+2$

b-          The tree will be 6 feet tall after 112 days (16 weeks)

c-          The possible inputs: $(x geq 0)$          The possible outputs $(y geq 2)$

Exercise 59
Step 1
1 of 2
The error is equating $5.4x=23.7$

While the correct is $5.4x=-23.7$

$5.4x=-23.7$

$dfrac {5.4x}{5.4}=dfrac {23.7}{5.4}$          (Divide each side by 5.4)

$x=-4.39$          (Solve for $x$)

Result
2 of 2
The correct solution is $x=-4.39$
Exercise 60
Step 1
1 of 3
Let us consider the given function $$color{blue} f(x)=4^x.$$
We can now make the table of the function.
begin{center}
begin{tabular}{ |c|c|c|c|c|c|c|c|c|c|c|c|c| }
hline
x & -2 & -1 & 0 & 1 & 2 \
hline
y & 0.0625 & 0.25 & 1 & 4 & 16 \
hline
end{tabular}
end{center}
And now we can draw the graph.\

Exercise scan

Step 2
2 of 3
Now we can completely describe the graph.

The domain of the function are all real numbers, we can write $x in (-infty, infty)$.

The range of the function are all positive real numbers, so we can write $y in (0, infty)$.

The $x$-intercept does not exist.

The $y$-intercept is the point $y=1$.

The function is not symmetric.

The function has one horizontal asymptote $y=0$.

The function is increasing for $x in (-infty, infty).$

The function does not have minimum or maximum points.

The function is continuous.

Result
3 of 3
The function is graphed and described as instructed.
Exercise 61
Step 1
1 of 5
a-

The domain is $x in (-1, 1, 2)$

The range is $y in(-2, 1, 2)$

Step 2
2 of 5
b-

The domain is: $(-2 leq x<1)$

The range is: $(-2 leq y<2)$

Step 3
3 of 5
c-

The domain is: $(-2 leq x< infty)$

The range is: $(-2 leq y< infty)$

Step 4
4 of 5
d-

The domain is: $(-infty leq x< infty)$

The range is: $(-2 leq y< infty)$

Result
5 of 5
begin{center}
renewcommand{arraystretch}{1.5}
begin{tabular}{|l|l|l|}
hline
Item & Domain & Range \
hline
$a-$ & $x in (-1, 1, 2)$ & $y in (-2, 1, 2)$ \
hline
$b-$ & $(-2 leq x < 1)$ & $(-2 leq y < 2)$ \
hline
$c-$ & $(-2 leq x < infty)$ & $(-2 leq y < infty)$ \
hline
$d-$ & $(-infty leq x < infty)$ & $(-2 leq y < infty)$ \
hline
end{tabular}
end{center}
Exercise 62
Step 1
1 of 2
Let us consider the given picture. We marked the angles of the given triangle with $alpha$, $beta$ and $gamma$. Now we have
$$
alpha +150^{circ} = 180^{circ} implies alpha =180^{circ}-150^{circ} implies alpha = 30^{circ}.
$$

Similarly,
$$
gamma +140^{circ} = 180^{circ} implies gamma =180^{circ}-140^{circ} implies gamma = 40^{circ}.
$$

Since angles in a triangle sum up to $180^{circ}$ we get

$$
begin{align*}
alpha + beta + gamma &= 180^{circ} \
30^{circ}+ beta +40^{circ} &=180^{circ} \
beta +70^{circ} &= 180^{circ} \
beta &= 1480^{circ}-70^{circ} implies beta = 110^{circ}.
end{align*}
$$

Finally, we have
$$
x=180^{circ}-110^{circ} = 70^{circ}.
$$

Therefore,
$$
color{#c34632} x=70^{circ}.
$$

Exercise scan

Result
2 of 2
$$
x=70^{circ}
$$
Exercise 63
Step 1
1 of 1
To apply this exercise
1. Invite your team.
2. Analyze tables, graphs, and equations as you work.
3. Determine the appropriate domain for each of the functions that describe Wynono’s descent .
Exercise 64
Step 1
1 of 6
a.

Let us determine the points of intersection of the functions

$$
f(x)= 2x^2-5x+6 hspace{5mm} text{and} hspace{5mm} g(x)= -2x^2-x+30.
$$

We can do that by using many different methods. we can use graphs, tables and equations.

Step 2
2 of 6
In order to determine the points of intersection of the two functions using graphs, we graph

$$
f(x)= 2x^2-5x+6 hspace{5mm} text{and} hspace{5mm} g(x)= -2x^2-x+30.
$$

Using the graph given below we see that the intersection points are

$$
color{#c34632} (-2, 24) hspace{5mm} text{color{default} and} hspace{5mm} (3, 9).
$$

Exercise scan

Step 3
3 of 6
Now, we can find the intersection point using tables. We form the table for function $$f(x)=2x^2-5x+6$$ first. We have
begin{center}
begin{tabular}{ |c|c|c|c|c|c|c|c|c| }
hline
x & -3 & -2 & -1 & 0 & 1 & 2 & 3 & 4 \
hline
y & 39 & 24 & 13 & 6 & 3 & 4 & 9 & 18 \
hline
end{tabular}
end{center}
Now we form the table for function $$g(x)= -2x^2-x+30 $$ and get
begin{center}
begin{tabular}{ |c|c|c|c|c|c|c|c|c| }
hline
x & -3 & -2 & -1 & 0 & 1 & 2 & 3 & 4 \
hline
y & 15 & 24 & 29 & 30 & 27 & 20 & 9 & -6 \
hline
end{tabular}
end{center}
Comparing these two tables we see that the intersection points are
$$color{red} (-2, 24) hspace{5mm} text{color{black} and} hspace{5mm} (3, 9). $$
Step 4
4 of 6
In order to find the intersection points using equations we solve the following system

$$
begin{align*}
y &= 2x^2-5x+6 \
y &= -2x^2 -x+30.
end{align*}
$$

Since the left sides of both equations are equal, we conclude that the right sides must be equal too. Therefore

$$
2x^2-5x+6 = -2x^2 -x+30.
$$

Now we solve for $x$.

$$
begin{align*}
2x^2-5x+6+2x^2+x-30 &=0 \
4x^2-4x-24 &= 0 \
4x^2+8x-12x-24 &=0 \
4x(x+2) – 12(x+2) &=0 \
(x+2) cdot (4x-12) &=0 \
x+2 = 0 hspace{3mm} vee hspace{3mm}4x-12 &= 0 \
x = -2 hspace{3mm} vee hspace{3mm}4x &=12 \
x = -2 hspace{3mm} vee hspace{3mm} x &=3
end{align*}
$$

In order to calculate $y$ we substitute $x=-2$ and $x=3$ in one of the two equations from the system. This yields

$$
begin{align*}
y &=2cdot (-2)^2-5 cdot (-2)+6 = 2 cdot 4 +10+6 = 8+16 = 24 \
y &=2cdot 3^2-5 cdot 3+6 = 2 cdot 9 -15+6 = 18-9 = 9.
end{align*}
$$

Therefore, the intersection points are

$$
color{#c34632} (-2, 24) hspace{5mm} text{color{default} and} hspace{5mm} (3, 9).
$$

Step 5
5 of 6
b.

Yes, you can make the graphing calculator calculate the points of intersection for you. It is very accurate as seen on the graph below.Exercise scan

Result
6 of 6
a. $(-2, 24)$ and $(3,9)$

b. Yes. It is very accurate.

Exercise 65
Step 1
1 of 1
To apply this exercise
1. Prepare your Learning Log.
2. Open a new page with title “Determining Points of Intersection” .
3. Explain how the points of intersection of graphs of functions can be determined.
4. Provide examples and a sketch.
Exercise 66
Step 1
1 of 2
Let us consider the given functions $$color{blue} f(x)=3x-5$$
and the function $g(x)$ defined with the following table
begin{center}
begin{tabular}{ |c|c|c|c|c|c|c|c|c|c|c|c|c| }
hline
x & -3 & -2 & -1 & 0 & 1 & 2 & 3 \
hline
g(x) & 21 & 17 & 13 & 9 & 5 & 1 & -3 \
hline
end{tabular}
end{center}
Now we can draw the graph of the both functions and find where they intersect.\
As seen on the graph below the point of intersection of the two graphs is $$color{red} (2, 1).$$

Exercise scan

Result
2 of 2
The point of intersection is $(2, 1)$.
Exercise 67
Step 1
1 of 4
a.

Let us consider the given expression
$$
color{#4257b2} 27^{1/3}.
$$

We can transform the given expression and get

$$
27^{1/3} = sqrt[3]{27} = sqrt[3]{3^3} = 3.
$$

Therefore,
$$
color{#c34632} 27^{1/3}=3.
$$

Step 2
2 of 4
b.

Let us consider the given expression
$$
color{#4257b2} (5x^7y^{-1})^{-2}.
$$

We can use the properties of exponents and transform the given expression

$$
(5x^7y^{-1})^{-2} = Big(5x^7 cdot frac{1}{y^1}Big)^{-2} = bigg( frac{5x^7}{y}bigg)^{-2} = bigg( frac{y}{5x^7}bigg)^2 = frac{y^2}{5^2 cdot (x^7)^2} = frac{y^2}{25x^{14}}.
$$

Therefore,
$$
color{#c34632} (5x^7y^{-1})^{-2}= frac{y^2}{25x^{14}}.
$$

Step 3
3 of 4
c.

Let us consider the given expression
$$
color{#4257b2} (3x^9 cdot y^{-4})(6x^{-8}y^4).
$$

We can use the properties of exponents and transform the given expression

$$
begin{align*}
(3x^9 cdot y^{-4})(6x^{-8}y^4) &= bigg( 3x^9 cdot frac{1}{y^4}bigg)bigg(6 cdot frac{1}{x^8} cdot y^4bigg)
= frac{3x^9}{y^4} cdot frac{6y^4}{x^8} \
&= frac{18x^9y^4}{y^4x^8} = 18x^{9-8} cdot y^{4-4}=18x^1 cdot y^0 \ &= 18x cdot 1 = 18x.
end{align*}
$$

Therefore,
$$
color{#c34632} (3x^9 cdot y^{-4})(6x^{-8}y^4)= 18x.
$$

Result
4 of 4
$$
begin{align*}
&text{a.} hspace{5mm} 27^{1/3} = 3 \
&text{b.} hspace{5mm} (5x^7y^{-1})^{-2}= frac{y^2}{25x^{14}} \
&text{c.} hspace{5mm} (3x^9 cdot y^{-4})(6x^{-8}y^4)= 18x \
end{align*}
$$
Exercise 68
Step 1
1 of 2
Let us consider the given condition
$$
color{#4257b2} 2^{x+4}=2^{3x-1}.
$$

In order for the equality to stand the exponents must be the same. Therefore,

$$
begin{align*}
2^{x+4}=2^{3x-1} implies x+4 &=3x-1 \ x-3x &= -1-4 \ -2x&=-5 \ x &= frac{-5}{-2} = frac{5}{2} = 2,5.
end{align*}
$$

We can conclude that if
$$
2^{x+4}=2^{3x-1}
$$
the value of $x$ is
$$
color{#c34632} x=2,5.
$$

Result
2 of 2
If $2^{x+4} = 2^{3x-1}$ then the value of $x$ is $x=2,5$.
Exercise 69
Step 1
1 of 4
Assuming the points are: $A=(-5,0)$ and $B=(0,3)$

a-          the graph of the points is the below.

Exercise scan

Step 2
2 of 4
The distance between two points $(x1, y1)$ and $(x2, y2)$ is given by the formula:

$d=sqrt {(y2-y1)^2+(x2-x1)^2}$

The distance between $A$ and $B$:

$d=sqrt {(3-0)^2+(0-(-5))^2}=sqrt {9+25}=sqrt {34} approx 5.83$ units

Step 3
3 of 4
b-

The slope the line is given by the formula:

$m=dfrac {y2-y1}{x2-x1}=dfrac {3-0}{0-(-5)}=dfrac {3}{5}$

Result
4 of 4
a-          The distance between two points $=sqrt {34} approx 5.83$ units

b-          The slope the line: $m=dfrac {3}{5}$

Exercise 70
Step 1
1 of 5
Assuming $y$ is the length of the snake after $x$ weeks

The initial length of the snake is 26 cm

The weekly growing is 2 cm

Step 2
2 of 5
a-

The equation that could represent this relation is:

$y=2x+26$

The graph below represents the equation

Exercise scan

Step 3
3 of 5
The next is the data table for the equation:\
\
begin{center}
renewcommand{arraystretch}{1.5}
begin{tabular}{|r|r|}
hline
Weeks $x$ & Snake length $y$ \
hline
0 & 26 \
hline
1 & 28 \
hline
2 & 30 \
hline
3 & 32 \
hline
4 & 34 \
hline
5 & 36 \
hline
6 & 38 \
hline
7 & 40 \
hline
8 & 42 \
hline
9 & 44 \
hline
10 & 46 \
hline
end{tabular}
end{center}
Step 4
4 of 5
b-

When the snake is 100 cm length, $y=100$

Substituting in the equation:

$y=2x+26$

$100=2x+26$

$2x=74$

$x=37$

The snake will be 100 cm long after 37 weeks.

Result
5 of 5
a-          The equation that represent this relation is:          $y=2x+26$

b-          The snake will be 100 cm long after 37 weeks.

Exercise 71
Step 1
1 of 8
The value that allows us to find the x-intercept is: $y=0$
Step 2
2 of 8
a-          $y=3x+6$          (Write the equation)

For x-intercept, Substitute $y=0$

$0=3x+6$

$x=-dfrac {6}{3}=-2$

x-intercept is $(-2, 0)$

Step 3
3 of 8
b-          $x=5y-10$          (Write the equation)

For x-intercept, Substitute $y=0$

$x=5(0)-10$          (Substitute $y=0$)

$x=0-10=-10$

x-intercept is $(-10, 0)$

Step 4
4 of 8
c-          $y=x^2$          (Write the equation)

For x-intercept, Substitute $y=0$

$0=x^2$

$x=0$

x-intercept is $(0, 0)$

Step 5
5 of 8
d-          $y=2x^2-4$          (Write the equation)

$2x^2=y+4$

$x^2=dfrac {y+4}{2}$

$$
x=sqrt {dfrac {y+4}{2}}
$$

For x-intercept, Substitute $y=0$

$x=pm sqrt {dfrac {0+4}{2}}=pm sqrt {2} approx pm 1.414$

x-intercept is $(1.414, 0)$ and $(-1.414, 0)$

Step 6
6 of 8
e-          $y=(x-5)^2$          (Write the equation)

For x-intercept, Substitute $y=0$

$0=(x-5)^2$

$x-5=0$

$x=5$

x-intercept is $(5, 0)$

Step 7
7 of 8
f-          $y=x^3-13$          (Write the equation)

$x^3=y+13$

$x=sqrt [3]{y+13}$

For x-intercept, Substitute $y=0$

$x=sqrt [3]{13} approx 2.3513$

x-intercept is $(2.3513, 0)$

Result
8 of 8
The value that allows us to find the x-intercept is: $y=0$

a-          x-intercept is $(-2, 0)$

b-          x-intercept is $(-10, 0)$

c-          x-intercept is $(0, 0)$

d-          x-intercepts are $(1.414, 0)$ and $(-1.414, 0)$

e-          x-intercept is $(5, 0)$

e-          x-intercept is $(2.3513, 0)$

Exercise 72
Step 1
1 of 5
a-

$y=dfrac {3}{5}x+1$          (Write the equation)

$dfrac {3}{5}x=y-1$          (Subtract 1 from each side)

$x=dfrac {5}{3}(y-1)$          (Multiply each side by $dfrac {5}{3}$

$$
x=dfrac {5}{3}(y-1)
$$

Step 2
2 of 5
b-

$3x+2y=6$          (Write the equation)

$3x=6-2y$          (Subtract $2y$ from each side)

$x=dfrac {6-2y}{3}$          (Divide each side by 3)

$$
x=dfrac {6-2y}{3}
$$

Step 3
3 of 5
c-

$y=x^2$          (Write the equation)

$x=sqrt {y}$          (The square root of each side)

$$
x=sqrt {y}
$$

Step 4
4 of 5
d-

$y=x^2-100$          (Write the equation)

$x^2=y+100$          (Add 100 to each side)

$x=sqrt {y+100}$          (The square root of each side)

$$
x=sqrt {y+100}
$$

Result
5 of 5
a-          $x=dfrac {5}{3}(y-1)$

b-          $x=dfrac {6-2y}{3}$

c-          $x=sqrt {y}$

d-          $x=sqrt {y+100}$

Exercise 73
Step 1
1 of 3
Assuming the size of the paper sheet is $22 mathrm{ ~cm} times 16 mathrm{ ~cm}$\
And the side length of the square we cut from the corner is $x mathrm{ ~cm}$\
The following table demonstrates the different volumes of the box for the different valus of $x$\
\
begin {center}
renewcommand{arraystretch}{2}
begin{tabular}{|r|r|r|r|}
hline
Square length (Unint) & Remaining Length & Remaining Width & Box volume \
hline
0 & 22 & 16 & 352 \
hline
1 & 20 & 14 & 280 \
hline
2 & 18 & 12 & 216 \
hline
3 & 16 & 10 & 160 \
hline
4 & 14 & 8 & 112 \
hline
5 & 12 & 6 & 72 \
hline
6 & 10 & 4 & 40 \
hline
7 & 8 & 2 & 16 \
hline
8 & 6 & 0 & 0 \
hline
end{tabular}
end {center}
Step 2
2 of 3
The following figure demonstrates the relation between the length of the cut square, the length and width of the box.Exercise scan
Result
3 of 3
We collect data for this relationship by assuming the length of the square $x=1$ cm in the firs time and increase the length by 1 unit each time.

All the possible inputs for our function are:          $(0 <x<8)$

Exercise 74
Step 1
1 of 3
$l=22$

$w=16$

Exercise scan

a) We consider the paper size:
Step 2
2 of 3
begin{center}
begin{tabular}{|| c|c|c| c||}
hline
$x$ & $22-2x$ & $16-2x$ & $V$ \ [0.5ex]
hline
1 & 22-2(1)=20 & 16-2(1)=14 & 1(20)(14)=280 \
hline
2 & 22-2(2)=18 & 16-2(2)=12 & 2(18)(12)=432 \
hline
3 & 22-2(3)=16 & 16-2(3)=10 & 3(16)(10)=480 \
hline
4 & 22-2(4)=14 & 16-2(4)=8 & 4(14)(8)=448 \
hline
5 & 22-2(5)=12 & 16-2(5)=6 & 5(12)(6)=360 \
hline
6 & 22-2(6)=10 & 16-2(6)=4 & 6(10)(4)=240 \[1ex]
hline
end{tabular}
end{center}
b) We give $x$ different values and determine the volume of the box:
Step 3
3 of 3
Exercise scan
c) We graph the volume as a function of the height $x$:
Exercise 75
Step 1
1 of 2
Exercise scan
a) We note:

$l$=the length of the paper

$w$=the width of the paper

$x$=the height of the box

The length of the box is:

$22-2x$,

while the width of the box is:

$16-2x$.

Step 2
2 of 2
$$
V=(l-2x)(w-2x)x
$$
b) We write the equation of the volume of the box:
Exercise 76
Step 1
1 of 8
$$
V=x(22-2x)(16-2x)
$$
a) In Problem 1-75 we got the equation of the volume in terms of the height $x$:
Step 2
2 of 8
$$
begin{cases}
x>0\
22-2x>0\
16-2x>0
end{cases}
$$
The function’s domain is limited because the height is smaller than the paper’s dimensions. Also the length and the width of the box must be positive values:
Step 3
3 of 8
$$
begin{cases}
x>0\
22>2x\
16>2x
end{cases}
$$

$$
begin{cases}
x>0\
11>x\
8>x
end{cases}
$$

We solve the system of equations:
Step 4
4 of 8
$$
xin (0,8)
$$
The domain is:
Step 5
5 of 8
$$
V=4x(11-x)(8-x)
$$
b) We rewrite the equation:
Step 6
6 of 8
The function $V$ has the zeros $0, 8,11$.Between the two consecutive zeros 0 and 8, the function is positive, having a local maximum at some point between 0 and 8, therefore the range of the volume is limited between 0 and this relative maximum.
Step 7
7 of 8
Exercise scan
c) We can connect the points with a smooth curve as the function has meaning for any real value of $x$ between 0 and 8 (the function is continuous).
Step 8
8 of 8
d) The graph has the domain $(0,8)$ and the range $(0,480]$.

It is continuous, increases when $xin (0,3)$ and decreases for $xin (3,8)$.

It has no asymptote.

Both ends go to 0.

Exercise 77
Step 1
1 of 3
$V=x(22-2x)(16-2x)$

Exercise scan

We use the graphing calculator to graph the function:
Step 2
2 of 3
The graph we made on paper is included in the above graph. The domain of our function is a subset of the set of real numbers, so the function we drew is a restriction of teh above function to the interval which makes sense for our model: $(0,8)$.
Step 3
3 of 3
The equation describes a polynomial of degree 3, therefore not a parabola.
Exercise 78
Step 1
1 of 1
To apply this exercise
1. Prepare a wide paper to use it as a poster.
2. Organize your findings of the representations of your function as well as the connections among the representations.
3. Use color, arrows, words, and any other useful tools to show everything you have learned.
Exercise 79
Step 1
1 of 1
To apply this exercise
1. Prepare your Learning Log.
2. Open a new title: “Mathematical Models “.
3. Explain the purpose for creating a mathematical model for a situation.
4. Give examples of ways in which your model would be useful.
Exercise 80
Step 1
1 of 5
$f(x)=x^2-2x+6$          (Given)

$g(x)=2x+11$          (Given)

For solving the system we graph both functions on the same grid and the intersections of both functions represent the solution.

Step 2
2 of 5
a-

From the graph, the point of intersection are:          $(-1, 9)$ and $(5, 21)$

Exercise scan

Step 3
3 of 5
b-

$$
begin{align*}
& f(x)+g(x)\
& =(x^2-2x+6)+(2x+11)\
& =x^2 cancel {-2x}+6 cancel {+2x}+11\
& =x^2+17\
\
end{align*}
$$

Step 4
4 of 5
c-

$$
begin{align*}
& f(x)-g(x)\
& =(x^2-2x+6)-(2x+11)\
& =x^2-2x+6 -2x-11\
& =x^2-4x-5\
\
end{align*}
$$

Result
5 of 5
a-          The point of intersection are:          $(-1, 9)$ and $(5, 21)$

b-                   $f(x)+g(x)=x^2+17$

c-                   $f(x)-g(x)=x^2-4x-5$

Exercise 81
Step 1
1 of 3
a.

The lengths of earthworms in centimeters are

$$
color{#4257b2} 4.0, hspace{3mm} 5.0, hspace{3mm} 5.8, hspace{3mm} 7.1, hspace{3mm} 7.8, hspace{3mm} 8.1, hspace{3mm} 8.2, hspace{3mm} 8.3, hspace{3mm} 8.4, hspace{3mm} 11.9, hspace{3mm} 12.0
$$

We can conclude right away that the minimum is $4$ and the maximum is $12$. The median is
$$
M=8.1.
$$
Since
$$
4.0, hspace{3mm} 5.0, hspace{3mm} 5.8, hspace{3mm} 7.1, hspace{3mm} 7.8
$$
we now have

$$
color{#4257b2} Q1=5.8.
$$

Similarly, since
$$
8.2, hspace{3mm} 8.3, hspace{3mm} 8.4, hspace{3mm} 11.9, hspace{3mm} 12.0
$$
we get
$$
color{#4257b2} Q3=8.4.
$$

Finally, we can calculate the Interquartile Range. We have

$$
IQR=Q3-Q1=8.4-5.8=2.6.
$$

Therefore, the Interquartile Range is
$$
color{#c34632} IQR=2.6.
$$

Step 2
2 of 3
b.

The boxplot of the data is given below.Exercise scan

Result
3 of 3
a. The Interquartile Range is $2.6$.

b. The boxplot of data is made.

Exercise 82
Step 1
1 of 4
a.

Let us consider the given expression
$$
color{#4257b2} 16^{5/4}.
$$

We can transform the given expression and get

$$
16^{5/4} = sqrt[4]{16^5} = big( sqrt[4]{16} big)^5 = big( sqrt[4]{2^4} big)^5 = 2^5 = 32.
$$

Therefore,
$$
color{#c34632} 16^{5/4}=32.
$$

Step 2
2 of 4
b.

Let us consider the given expression
$$
color{#4257b2} (x^5y^4)^{1/2}.
$$

We can use the properties of exponents and transform the given expression

$$
begin{align*}
(x^5y^4)^{1/2} &= (x^5)^{1/2} cdot (y^4)^{1/2} = x^{5 cdot frac{1}{2}} cdot y^{4 cdot frac{1}{2}} = x^{5/2} cdot y^2 \ &= sqrt{x^5} cdot y^2 = sqrt{x^4 cdot x} cdot y^2 = x^2y^2 sqrt{x}. end{align*}
$$

Therefore,
$$
color{#c34632} (x^5y^4)^{1/2}= x^2y^2 sqrt{x}.
$$

Step 3
3 of 4
c.

Let us consider the given expression
$$
color{#4257b2} (x^2y^{-1})(x^{-3}y)^0.
$$

We can use the properties of exponents and transform the given expression

$$
begin{align*}
(x^2y^{-1})(x^{-3}y)^0 &= bigg( x^2 cdot frac{1}{y^1}bigg) cdot 1 = frac{x^2}{y}.
end{align*}
$$

Therefore,
$$
color{#c34632} (x^2y^{-1})(x^{-3}y)^0= frac{x^2}{y}.
$$

Result
4 of 4
$$
begin{align*}
&text{a.} hspace{5mm} 16^{5/4}=32 \
&text{b.} hspace{5mm} (x^5y^4)^{1/2}= x^2y^2 sqrt{x} \
&text{c.} hspace{5mm} (x^2y^{-1})(x^{-3}y)^0= frac{x^2}{y} \
end{align*}
$$
Exercise 83
Step 1
1 of 2
Let us consider the given function $$color{blue} f(x)=sqrt[3]{x+2}.$$
We can now make the table of the function.
begin{center}
begin{tabular}{ |c|c|c|c|c|c|c|c|c|c|c|c|c| }
hline
$x$ & -10 & -3 & -2 & -1 & 0 & 6 & 25 \
hline
$f(x)$ & -2 & -1 & 0 & 1 & $sqrt[3]{2} approx 1.26$ & 2 & 3 \
hline
end{tabular}
end{center}
And now we can draw the graph. The graph is seen below.\
\
We can see in the table and on the graph that $x$-intercept is $x=-2$, while the $y$=intercept is $y=sqrt[3]{2} approx 1.26$. \
\
The domain are all real number, hence we can write $color{red} x in (-infty, infty)$. The range is just the same, therefore $color{red} y in (-infty, infty)$. \

Exercise scan

Result
2 of 2
The function is graphed and the domain and the range are all the real numbers, hence $(-infty, infty)$.
Exercise 84
Step 1
1 of 2
a-

Domain is:          $x in (-2, -1, 2)$

Range is:          $y in (-1, 0, 1)$

b-

Domain is:          $(-1<x leq 1)$

Range is:          $(-1 leq y<2)$

c-

Domain is:          $(-1<x < infty)$

Range is:          $(-1<y<infty)$

d-

Domain is:          $(-infty<x < infty)$

Range is:          $(-infty<y<infty)$

Result
2 of 2
begin{center}
begin{tabular}{|r|r|r|}
hline
Item & Domain & Range \
hline
a- & $x in (-2, -1, 2)$ & $y in (-1, 0, 1)$ \
hline
b- & $(-1 < x leq 1)$ & $(-1 leq y < 2)$ \
hline
c- & $(-1 < x < infty)$ & $(-1 < y < infty)$ \
hline
d- & $(-infty < x < infty)$ & $(-infty < y < infty)$ \
hline
end{tabular}
end{center}
Exercise 85
Step 1
1 of 2
Assuming the width of the rectangle is $w$

The length of the rectangle $l=4w$          (Given)

$l+w=22$          (Given)

$4w+w=22$          (Substituting $4w$ for $l$)

$5w=22$          (Simplify)

$w=4.4$ Units          (Solve for $w$)

$l=4w=4cdot 4.4=17.6$ units          (Solve for $l$)

Result
2 of 2
The length of the rectangle $l=17.6$

The width of the rectangle $w=4.4$

Exercise 86
Step 1
1 of 2
Let us calculate exactly where the given lines
$$
color{#4257b2} y=2x-frac{7}{6} hspace{4mm} text{color{default} and} hspace{4mm} y=3-3x
$$
intersect. To find their intersection using algebra we solve the following system of equations

$$
begin{align*}
y &=2x-frac{7}{6} \
y &=3-3x.
end{align*}
$$

Since the left sides of both equations are equal, we can conclude that the right sides of the equations must be equal. Therefore we get

$$
2x-frac{7}{6} = 3-3x.
$$

Now we solve this equation for $x$.

$$
begin{align*}
2x-frac{7}{6} &= 3-3x \
2x+3x &= 3+ frac{7}{6} \
5x &= frac{18}{6} + frac{7}{6} \
5x &= frac{25}{6} \
x&= frac{25}{6} cdot frac{1}{5} = frac{5}{6}.
end{align*}
$$

To calculate $y$ we substitute $x=5/6$ in $y=3-3x$ and get

$$
y=3-3cdot frac{5}{6} = 3-frac{5}{2} = frac{6}{2}- frac{5}{2}= frac{1}{2}.
$$

Finally, we conclude that the point of intersection for two given functions is
$$
color{#c34632} (x, y) = (frac{5}{6}, frac{1}{2}).
$$

Result
2 of 2
The point of intersection for the two given functions is
$$
(frac{5}{6}, frac{1}{2}).
$$
Exercise 87
Step 1
1 of 4
a-

$w^2+4w=0$          (Given)

$w(w+4)=0$          (Factor out $w$)

$w=0$ or $w=-4$

Step 2
2 of 4
b-

$5w^2-2w=0$          (Given)

$w(5w-2)=0$          (Factor out $w$)

$w=0$ or $w=dfrac {2}{5}$

Step 3
3 of 4
c-

$w^2=6w$          (Given)

$w^2-6w=0$

$w(w-6)=0$          (Factor out $w$)

$w=0$ or $w=6$

Result
4 of 4
a-          $w=0$ or $w=-4$

b-          $w=0$ or $w=dfrac {2}{5}$

c-          $w=0$ or $w=6$

Exercise 88
Step 1
1 of 2
A nonprofit consumer health organization measured the fat content of five low-fat raspberry muffins to have
$$
color{#4257b2} 6, hspace{3mm} 8, hspace{3mm} 8, hspace{3mm} 9, hspace{3mm} 7
$$
grams of fat. Let us calculate the mean first. The mean value is
$$
frac{6+8+8+9+7}{5} = frac{38}{5} = color{#c34632} 7,6.
$$

The next step is to calculate the distances from the mean value. We have

$$
begin{align*}
6-7,6 &= -1.6 \
8-7,6 &= 0,4 \
9-7,6 &= 1,4 \
7-7,6 &= -0,6.
end{align*}
$$

Now we calculate the sum of squares of the distances from the mean value. We have

$$
begin{align*}
(-1,6)^2+(0,4)^2+(0,4)^2+(1,4)^2 + (-0,6)^2 &= 2,56+0,16+0,16+1,96+0,36 \ &=5,2. end{align*}
$$

Finally, we can calculate the sample standard deviation

$$
sqrt{frac{5,2}{5-1}} = sqrt{frac{5,2}{4}} = sqrt{1,3} approx color{#c34632} 1,14.
$$

Therefore, $text{color{#c34632} the mean value is $7,6$g and the sample standard deviation is $1,14$g.}$

Result
2 of 2
The mean value is $7,6$g and the sample standard deviation is $1,14$g.
Exercise 89
Step 1
1 of 3
The graph of the function $h(x)=x^2-5$ crosses the x-axis when $h(x)=0$

$0=x^2-5$          (Substitute 0 for $h(x)$)

$x^2=5$

$x= pm sqrt {5} approx 2.236$

The graph crosses the x-axis at:          $x approx 2.236$ and $x approx -2.236$

Step 2
2 of 3
Exercise scan
Result
3 of 3
The graph crosses the x-axis at:          $x approx 2.236$ and $x approx -2.236$
Exercise 90
Step 1
1 of 2
The equation of the x-axis is:

$$
y=0
$$

The equation of the y-axis is:

$$
x=0
$$

Result
2 of 2
The equation of the x-axis is:          $y=0$

The equation of the y-axis is:          $x=0$

Exercise 91
Step 1
1 of 5
a.

Let us multiply the given expression

$$
begin{align*}
(x-1)(x+1) &= x cdot x + x cdot 1 -1 cdot x -1 cdot 1 \
&= x^2+x-x-1 \ &= x^2 -1.
end{align*}
$$

Therefore, we conclude
$$
color{#c34632} (x-1)(x+1) = x^2-1.
$$

Step 2
2 of 5
b.

Let us multiply the given expression

$$
begin{align*}
2x(x+1)(x+1) &= 2x(x cdot x + x cdot 1 +1 cdot x +1 cdot 1) \
&= 2x(x^2+x+x+1) \ &= 2x(x^2+2x+1) \ &= 2x cdot x^2 + 2x cdot 2x + 2x cdot 1 \ &=2x^3+4x^2 +2x.
end{align*}
$$

Therefore, we conclude
$$
color{#c34632} 2x(x+1)(x+1) = 2x^3+4x^2 +2x.
$$

Step 3
3 of 5
c.

Let us multiply the given expression. we use part (a) of the exercise and get

$$
begin{align*}
(x-1)(x+1)(x-2) &= (x^2-1) cdot (x-2) \
&= x^2 cdot x +x^2 cdot (-2) -1 cdot x -1 cdot (-2) \
&= x^3-2x^2-x+2.
end{align*}
$$

Therefore, we conclude
$$
color{#c34632} (x-1)(x+1)(x-2) = x^3-2x^2-x+2.
$$

Step 4
4 of 5
d.

Consider the given function
$$
color{#4257b2} y=x^3-2x^2-x+2.
$$

First, we can find the $x$-intercept. We do that by substituting $y=0$ in the given function. This yields

$$
x^3-2x^2-x+2 = 0.
$$

In order to solve this easily, we can use part (c) of the exercise and factor the given polynomial on the left side of the equation. This gives us

$$
begin{align*}
x^3-2x^2-x+2 = 0 &implies (x-1)(x+1)(x-2)=0 \ &implies x-1 = 0 vee x+1 =0 vee x-2=0 \
&implies x=1 vee x=-1 vee x=2. end{align*}
$$

We can conclude that $x$-intercept points are
$$
color{#c34632} x=1, hspace{3mm} x=-1 hspace{3mm} text{color{default} and} hspace{3mm} x=2.
$$

Let us now calculate the $y$-intercept point. In order to do this, we substitute $x=0$ in the given function. This gives

$$
y=0^3-2 cdot 0^2 -0+2 = 0-0-0+2 = 2.
$$

Therefore, we can conclude that the $y$-intercept point is
$$
color{#c34632} y=2.
$$

Result
5 of 5
a. $(x-1)(x+1) = x^2-1$

b. $2x(x+1)(x+1) = 2x^3+4x^2 +2x$

c. $(x-1)(x+1)(x-2) = x^3-2x^2-x+2$

d. The $x$-intercept points are $x=1$. $x=-1$ and $x=2$, while the $y$-intercept point is $y=2$.

Exercise 92
Step 1
1 of 5
a-          $y-2x=3$          (Given)

Domain is:          $(-infty<x<infty)$

Range is:          $(-infty<x<infty)$

b-          $y-3=x^2$          (Given)

Domain is:          $(-infty<x<infty)$

Range is:          $(3 leq y<infty)$

Step 2
2 of 5
Exercise scan
Step 3
3 of 5
c-

$y-2x=3$          (Given)

x-intercept is:          $(-1.5, 0)$

y-intercept is:          $(0, 3)$

$y-3=x^2$          (Given)

There is no x-intercepts because the equation does not have real solutions

y-intercept is:          $(0, 3)$

Step 4
4 of 5
d-

To get the intersection of the two functions without looking at the graph, we solve both equations.

$y-2x=3$          (Write the first equation)

$y=2x+3$          (Solve for $y$)

$y-3=x^2$          (Write the second equation)

$2x+3-3=x^2$          (Substituting $2x+3$ for $y$)

$x^2-2x=0$

$x(x-2)=0$          (Factor out $x$)

$x=0$ or $x-2=0$          (Zero product property)

$x=0$ or $x=2$          (Solve for $x$)

Substituting 0 for $x$ in the first equation:

$y-2(0)=3$

$y=3$

Substituting 2 for $x$ in the first equation:

$y-2(2)=3$

$y=7$

The points of intersection are $(0, 3)$ and $(2, 7)$

Result
5 of 5
a-          $y-2x=3$          (Given)

Domain is:          $(-infty<x<infty)$          Range is:          $(-infty<x<infty)$

x-intercept is:          $(-1.5, 0)$          y-intercept is:          $(0, 3)$

b-          $y-3=x^2$          (Given)

Domain is:          $(-infty<x<infty)$          Range is:          $(3 leq y<infty)$

There is no x-intercepts because the equation does not have real solutions

y-intercept is:          $(0, 3)$

The points of intersection are $(0, 3)$ and $(2, 7)$

Exercise 93
Step 1
1 of 3
$angle BAC cong angle EAC$          (Common angle for both triangles)

$angle ACB cong angle AED$          (Both are right angles)

$angle CBA cong angle EDA$          (Triangle sum theorem)

So, $triangle ABC sim triangle ADE$

Step 2
2 of 3
a-          $dfrac {y}{x}=dfrac {n}{m}$          ($dfrac {BC}{AC}=dfrac {DE}{AE}$ Both represent the tangent of the common angle)

b-          $dfrac {n}{y}=dfrac {m}{x}$          (The ratio of similarity)

Result
3 of 3
$triangle ABC sim triangle ADE$          (Triangle sum theorem)

a-          $dfrac {y}{x}=dfrac {n}{m}$

b-          $dfrac {n}{y}=dfrac {m}{x}$

Exercise 94
Step 1
1 of 2
While observing the five birds from pet store it was notices that the birds ate
$$
color{#4257b2} 60, hspace{3mm} 60, hspace{3mm} 50, hspace{3mm} 40, hspace{3mm} 50
$$
grams of food each. Let us calculate the mean first. The mean value is
$$
frac{60+60+50+40+50}{5} = frac{260}{5} = color{#c34632} 52.
$$

The next step is to calculate the distances from the mean value. We have

$$
begin{align*}
60-52 &= 8 \
50-52&= -2 \
40-52 &= -12.
end{align*}
$$

Now we calculate the sum of squares of the distances from the mean value. We have

$$
begin{align*}
8^2+8^2+(-2)^2+(-12)^2 + (-2)^2 &= 64+64+4+144+4 =280. end{align*}
$$

Finally, we can calculate the sample standard deviation

$$
sqrt{frac{280}{5-1}} = sqrt{frac{280}{4}} = sqrt{70} approx color{#c34632} 8,37.
$$

Therefore, $text{color{#c34632} the mean value is $52$g and the sample standard deviation is $8,37$g.}$

Result
2 of 2
The mean value is $52$g and the sample standard deviation is $8,37$g.
Exercise 95
Step 1
1 of 3
a-

$-2(x+4)=35-(7-4x)$          (Write the equation)

$-2x-8=35-7+4x$          (Distributive property)

$4x+2x=-8-35+7$          (Grouping similar terms)

$6x=-36$          (Simplifying)

$x=-6$          Solve for $x$

Step 2
2 of 3
b-

$dfrac {x-4}{7}=dfrac {8-3x}{5}$          (Write the equation)

$5(x-4)=7(8-3x)$          (Multiply each side by 35)

$5x-20=56-21x$          (Distributive property)

$5x+21x=56+20$          (Grouping similar terms)

$26x=76$          (Simplifying)

$x=dfrac {38}{13}$          Solve for $x$

Result
3 of 3
a-          $x=-6$

b-          $x=dfrac {38}{13}$

Exercise 96
Step 1
1 of 5
Consider the given points
$$
color{#4257b2} A(3,2) hspace{3mm} text{color{default} and} hspace{3mm} B(-21, 0).
$$

a.

Let us calculate the slope of the line $overline{AB}$. Let

$$
A(3,2)=(x_1, y_1) hspace{3mm} text{color{default} and} hspace{3mm} B(-21, 0)=(x_2, y_2).
$$

Now we calculate the slope

$$
m=frac{y_2-y_1}{x_2-x_1} = frac{0-2}{-21-3} = frac{-2}{-24} = frac{1}{12}.
$$

Therefore, the slope of the line $overline{AB}$ is
$$
color{#c34632} m=frac{1}{12}.
$$

Step 2
2 of 5
b.

Let us calculate the length of the line $overline{AB}$. Let

$$
A(3,2)=(x_1, y_1) hspace{3mm} text{color{default} and} hspace{3mm} B(-21, 0)=(x_2, y_2).
$$

Now we calculate the length

$$
begin{align*}
d &=sqrt{(x_2-x_1)^2+(y_2-y_1)^2}= sqrt{(-21-3)^2+(0-2)^2} \
&= sqrt{(-24)^2+(-2)^2} = sqrt{576+4} = sqrt{580} = sqrt{4 cdot 145} = 2sqrt{145}. end{align*}
$$

Therefore, the length of the line $overline{AB}$ is
$$
color{#c34632} d= 2sqrt{145}.
$$

Step 3
3 of 5
c.

Let us calculate the midpoint of the line $overline{AB}$. Let

$$
A(3,2)=(x_1, y_1) hspace{3mm} text{color{default} and} hspace{3mm} B(-21, 0)=(x_2, y_2).
$$

Now we calculate the length

$$
begin{align*}
bigg( frac{x_1+x_2}{2}, frac{y_1+y_2}{2} bigg) &=bigg( frac{3+(-21)}{2}, frac{2+0}{2} bigg) \
&= bigg( frac{-18}{2}, frac{2}{2} bigg) \ &= (-9, 1).
end{align*}
$$

Therefore, the midpoint of the line $overline{AB}$ is
$$
color{#c34632} (-9,1).
$$

Step 4
4 of 5
d.

Let us calculate the equation of the line $overline{AB}$. The equation has the form

$$
color{#4257b2} y=k cdot x + n.
$$

In part (a) of the exercise we have already calculated the slope
$$
k=frac{1}{12}.
$$

In order to calculate $n$, we substitute the coordinates of the point $A(3,2)$. Therefore, we substitute $x=3$ and $y-2$. This yields

$$
begin{align*}
y=k cdot x + n implies 2&= frac{1}{12} cdot 3 + n \ 2 &= frac{1}{4} + n \
n &= 2-frac{1}{4} = frac{8}{4} – frac{1}{4} = frac{7}{4}.
end{align*}
$$

Finally, the equation of the line $overline{AB}$ is

$$
color{#c34632} y=frac{1}{12}x + frac{7}{4}.
$$

Result
5 of 5
a. The slope of the line $overline{AB}$ is $frac{1}{12}$.

b. The length of the line $overline{AB}$ is $2 sqrt{145}$.

c. The midpoint of the line $overline{AB}$ is $(-9, 1)$.

d. The equation of the line $overline{AB}$ is
$$
y=frac{1}{12} x + frac{7}{4}.
$$

Exercise 97
Step 1
1 of 3
$h(x)=2x^2+4x-6$          (Write the equation)

The domain of the function is:          $(-infty<x<infty)$

The range of the function is:          $(-8 leq y<infty)$

x-intercepts are:          $(-3, 0)$ and $(1, 0)$

y-intercept is:          $(0, -6)$ and $(1, 0)$

Step 2
2 of 3
Exercise scan
Result
3 of 3
The domain of the function is:          $(-infty<x<infty)$

The range of the function is:          $(-8 leq y<infty)$

Exercise 98
Step 1
1 of 3
RECALL:
$\\$The domain is the set of all x-values while the range is the set of y-values.$

$(a)$

$Scanning the graph from left to right shows that the x values are from -3 to 3 therefore the domain is$$text{color{#4257b2}[-3, 3]$.
$\\$Scanning the graph from bottom to top shows that the y values -2, 1, and 3. Therefore the range is $color{#4257b2}left{-2, 1, 3right}$.}$

Step 2
2 of 3
(b)
Scanning the graph from left to right shows that there is only one x value which is 2. Therefore the domain is $color{#4257b2}left{2right}$.
$\\$The graph is continuous from bottom to top therefore the range is$$text{color{#4257b2}left(-infty, inftyright)$.}$
Step 3
3 of 3
(c)
$\\$
Scanning the graph from left to right shows that the x values are from -2 to positive infinty therefore the domain is$$text{color{#4257b2}[-2, +infty)$.
$\\$There are no excluded y-values therefore that the range is $color{#4257b2}left(-infty+inftyright)$.}$
Exercise 99
Step 1
1 of 2
Rewrite expressions using the fact that $a^{-n}=dfrac{1}{a^{n}}$ and the usual laws for exponents $a^{m}a^{n}=a^{mn}$ ; (a) $=dfrac{1}{25}$ ; (b) $=dfrac{x}{y^{2}}$ ; (c) $=dfrac{1}{x^{2}y^{2}}$ ; (d) $=dfrac{b^{10}}{a}$
Result
2 of 2
see answers
Exercise 100
Step 1
1 of 3
The volume of water added in a cylindrical beaker $V=h pi r^2$          ($h$ is the height of the water, $pi r^2$ is the area of the base of the cylindrical beaker.

Solving the equation $V=h pi r^2$ for $h$, we get.

$h=dfrac {V}{pi r^2}$

From the given graph it is clear that Area$_{B}>$Area$_{A}>$Area$_{C}$

The independent variable is $V$ the volume of water.

The dependent variable is $h$ the height of the water.

Step 2
2 of 3
Exercise scan
Result
3 of 3
The independent variable is $V$ the volume of water.

The dependent variable is $h$ the height of the water.

Exercise 101
Step 1
1 of 4
(a)
**Box plot**
| 0|2.6 |5.6 |10.1 | 17.7|
|–|–|–|–|–|
|0 |2.9 |6.4 |11.2 |21.4 |
|0 | 4.2| 8.0|13.5 | 22.0|
|0 |4.4 |8.9 |15.1 |22.2 |
| 1.7| 5.1|9.7 |16.3 |36.5 |
Step 2
2 of 4
**Histogram**
![‘slader’](https://slader-solution-uploads.s3.amazonaws.com/c10d8b9a-b5c3-4e4f-a55a-4870911f634a-1634855440006700.png)
Step 3
3 of 4
(b)
**Mean** is $9.82$.
**Sample Standard Deviation** is $9.05$
Step 4
4 of 4
(c)
This is not the right decision because there are only two homes for that condition.
Exercise 102
Step 1
1 of 2
(a)
Compare graphically
![‘slader’](https://slader-solution-uploads.s3.amazonaws.com/043e46d3-7fd3-4973-be04-27a5e0fa4ec1-1635026484596993.jpeg)
Step 2
2 of 2
(b)
**For Soda Cans**
Count, N: 30

Mean, x̄: 370.4

Variance, s2: 33.972413793103

**For Free Sugar Cans**

Count, N: 30

Mean, x̄: 357.46666666667

Variance, s2: 26.257471264368

Exercise 103
Step 1
1 of 2
(a)
**Minimum number** is $textcolor{#c34632}{1}$.
**First Quartile** is $textcolor{#c34632}{19.5}$.
**Median number** is $textcolor{#c34632}{29}$.
**Third Quartile** is $textcolor{#c34632}{39}$.
**Maximum number** is $textcolor{#c34632}{76}$.
Step 2
2 of 2
(b)
The distribution of coffee per hour
$$=dfrac{1444}{48}approx 30hspace{1cm}textrm{cup/hour}$$
Exercise 104
Step 1
1 of 3
a.

Let us solve the following equation
$$
color{#4257b2} x^2+3x-3=0.
$$

Since the expression of the left is a quadratic function we can use the quadratic formula

$$
x = frac{-b pm sqrt{b^2-4ac}}{2a}.
$$
We have

$$
a=1 hspace{12mm} b=3 hspace{12mm} c=-3.
$$

Hence, we have

$$
begin{align*}
x &= frac{-3 pm sqrt{3^2-4 cdot 1 cdot (-3)}}{2 cdot 1} \
x &= frac{-3 pm sqrt{9+12}}{2} \
x &= frac{-3 pm sqrt{21}}{2} \
x &= frac{-3 + sqrt{21}}{2} approx 0,8 hspace{3mm} text{or} hspace{3mm} frac{-3 – sqrt{21}}{2} approx -3,8.
end{align*}
$$

Therefore, the solutions are
$$
color{#c34632} x=frac{-3 + sqrt{21}}{2} approx 0,8 hspace{3mm} text{color{default}or} hspace{3mm} x=frac{-3 – sqrt{21}}{2} approx -3,8.
$$

Step 2
2 of 3
b.

Let us solve the following equation
$$
color{#4257b2} 3x^2-7x=12.
$$
First we transform the equation a little bit and get

$$
3x^2-7x-12=0.
$$

Since the expression of the left is a quadratic function we can use the quadratic formula

$$
x = frac{-b pm sqrt{b^2-4ac}}{2a}.
$$
We have

$$
a=3 hspace{12mm} b=-7 hspace{12mm} c=-12.
$$

Hence, we have

$$
begin{align*}
x &= frac{-(-7) pm sqrt{(-7)^2-4 cdot 3 cdot (-12)}}{2 cdot 3} \
x &= frac{7 pm sqrt{49+144}}{6} \
x &= frac{7 pm sqrt{193}}{6} \
x &= frac{7 + sqrt{193}}{6} approx 3,5 hspace{3mm} text{or} hspace{3mm} frac{7 – sqrt{193}}{6} approx -1,1.
end{align*}
$$

Therefore, the solutions are
$$
color{#c34632} x=frac{7 + sqrt{193}}{6} approx 3,5 hspace{3mm} text{color{default}or} hspace{3mm} x=frac{7 – sqrt{193}}{6} approx -1,1.
$$

Result
3 of 3
$$
begin{align*}
&text{a.} hspace{3mm} x=frac{-3 + sqrt{21}}{2} approx 0,8 hspace{3mm} text{color{default}or} hspace{3mm} x=frac{-3 – sqrt{21}}{2} approx -3,8 \
&text{b.} hspace{3mm} x=frac{7 + sqrt{193}}{6} approx 3,5 hspace{3mm} text{color{default}or} hspace{3mm} x=frac{7 – sqrt{193}}{6} approx -1,1 \
end{align*}
$$
Exercise 105
Step 1
1 of 3
The equilateral triangle perimeter $p=3x$ where $x$ is the side length of the triangle.\
The following table represents the parameter of triangles with different side lengths
begin{center}
renewcommand{arraystretch}{1.5}
begin{tabular}{|c|c|}
hline
Side length $x$ & Perimeter $p$ \
hline
3 & 9 \
hline
4 & 12 \
hline
5 & 15 \
hline
6 & 18 \
hline
7 & 21 \
hline
8 & 24 \
hline
9 & 27 \
hline
end{tabular}
end{center}
Step 2
2 of 3
Exercise scan
Result
3 of 3
The perimeter of the equilateral triangle can be represented by the equation $p=3x$
Exercise 106
Step 1
1 of 5
Let us graph the line $$color{blue} y=-frac{1}{4}x+2.$$
We can now make the table of the function.
begin{center}
begin{tabular}{ |c|c|c|c| }
hline
x & 0 & 8 \
hline
y & 2 & 0 \
hline
end{tabular}
end{center}
And now we can draw the graph.\

Exercise scan

Step 2
2 of 5
a.

Let us sketch the line that is perpendicular to the line
$$
y=-frac{1}{4}x+2
$$
and passes through the point $(5, 5)$.

Exercise scan

Step 3
3 of 5
b.

Let us write the equation of the perpendicular line to the line
$$
y=-frac{1}{4}x+2.
$$
We need to find the equation

$$
color{#4257b2} y=k cdot x+n.
$$

We can find the coefficient $k$ using the fact that the two lines are perpendicular. We have

$$
k=-frac{1}{-frac{1}{4}}=4.
$$

In order to find $n$ we use the fact that our wanted line passes through $(5,5)$. We substitute $k=4$, $x=5$ and $y=5$ and get

$$
5=4 cdot 5 +n implies 5=20+n implies n=5-20 =-15.
$$

Therefore, the equation of the perpendicular line to the line $y=-frac{1}{4}x+2$ is

$$
color{#c34632} y=4x-15.
$$

Step 4
4 of 5
c.

Let us find where do lines

$$
y=-frac{1}{4}x+2 hspace{5mm} text{and} hspace{5mm} y=4x-15
$$
intersect. In order to do that we solve the following system

$$
begin{align*}
y &=-frac{1}{4}x+2 \
y &=4x-15.
end{align*}
$$

Since left sides of both equations are the same we conclude that the right sides of both equations must be equal too. Therefore
$$
-frac{1}{4}x+2 = 4x-15.
$$

Now we solve for $x$.

$$
begin{align*}
-frac{1}{4}x+2 = 4x-15 implies -frac{1}{4}x -4x &= -2-15 \
-frac{1}{4}x -frac{16}{4}x &= -17 \ -frac{17}{4}x &=-17 \ x &=-17 cdot Big(-frac{4}{17} Big) =color{#4257b2} 4.
end{align*}
$$

Now we find $y$ by substituting $x=4$ in $y=4x-15$. This yields

$$
y=4 cdot 4 -15 = 16-15=color{#4257b2} 1.
$$

Therefore, the lines

$$
y=-frac{1}{4}x+2 hspace{5mm} text{and} hspace{5mm} y=4x-15
$$
intersect in the point
$$
color{#c34632} (4,1).
$$

Result
5 of 5
a. We graphed the line $y=-frac{1}{4}x+2$ and the line that is perpendicular to it and passes through $(5,5)$.

b. The equation of the perpendicular line to $y=-frac{1}{4}x+2$ is $y=4x-15.$

c. The point of intersection of the two lines is $(4, 1)$.

Exercise 107
Step 1
1 of 4
a.

The function is graphed as seen below.

The domain of the graphed function are all real numbers except for $0$. Therefore, we write that the domain is

$$
color{#c34632} (-infty, 0) cup (0, infty).
$$

The range of the graphed function are all real numbers except for $0$. Therefore, we write that the range is

$$
color{#c34632} (-infty, 0) cup (0, infty).
$$

Exercise scan

Step 2
2 of 4
b.

The function is graphed as seen below.

The domain of the graphed function are all real numbers between $-5$ and $6$ including $6$. Therefore, we write that the domain is

$$
color{#c34632} (-5, 6].
$$

The range of the graphed function are all real numbers between $-4$ and $2$ including $2$. Therefore, we write that the range is

$$
color{#c34632} (-4, 2].
$$

Exercise scan

Step 3
3 of 4
c.

The function is graphed as seen below.

The domain of the graphed function are all real numbers. Therefore, we write that the domain is

$$
color{#c34632} (-infty, infty).
$$

The range of the graphed function are all real numbers smaller than $1$ including $1$. Therefore, we write that the range is

$$
color{#c34632} (-infty, 1].
$$

Exercise scan

Result
4 of 4
a. The domain is $(-infty, 0) cup(0, infty)$ and the range is $(-infty, 0) cup(0, infty)$.

b. The domain is $(-5,6]$ and the range is $(-4,2]$.

c. The domain is $(-infty, infty)$ and the range is $(-infty, 1]$.

Exercise 108
Step 1
1 of 2
The functions

$$
begin{align*}
y &= x^2 \ y &= -3x^2 \ y&= -0,25x^2
end{align*}
$$

are sketched on the same set of axes as seen on the graph below.

Looking at the graph we notice that the negative coefficient of $x^2$ makes the graph $text{$text{color{#c34632} open downward. \}$}$

Exercise scan

Result
2 of 2
The three functions are sketched as instructed. The negative coefficient of $x^2$ makes the graph open downward.
Exercise 109
Step 1
1 of 2
$f(x)=2x^2-3x+4$          (Given)

$g(x)=x^2+5x-3$          (Given)

To find the points of intersection of both functions $f(x)$ and $g(x)$ algebraically, we equate both functions.

$f(x)=g(x)$

$2x^2-3x+4=x^2+5x-3$

$2x^2-x^2-3x-5x+4+3=0$          (Grouping similar terms)

$x^2-8x+7=0$          (Simplifying)

$(x-7)(x-1)=0$          (Factoring)

$x-7=0$ or $x-1=0$          (Zero product property)

$x=7$ or $x=1$          (Solve for $x$)

For $x=7$

$f(7)=2(7)^2-3(7)+4=98-21+4=81$

Checking for $g(x)$

$g(7)=49+35-3=81$ checkmark

For $x=1$

$f(1)=2(1)^2-3(1)+4=2-3+4=3$

Checking for $g(x)$

$g(1)=1+5-3=3$ checkmark

The points of intersection are:          $(7, 81)$ and $(1, 3)$

Result
2 of 2
The points of intersection are:          $(7, 81)$ and $(1, 3)$
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