Core Connections Integrated 2
Core Connections Integrated 2
2nd Edition
Brian Hoey, Judy Kysh, Leslie Dietiker, Tom Sallee
ISBN: 9781603283489
Table of contents
Textbook solutions

All Solutions

Page 483: Questions

Exercise 1
Step 1
1 of 3
a. Since the area of the disk is $A=pi r^2$, the area will quadrupel if the radius doubles and thus the mass will quadrupel also.

b.

Exercise scan

Step 2
2 of 3
c. The positive half of a quadratic function

d. Replace $A$ with the mass in the equation of the area of the disk:

$$
m=pi r^2
$$

e. The mass would be four times as largest mass measured.

Result
3 of 3
a. Quadratic

b. Graph

c. Positive half quadratic function

d. $m=pi r^2$

e. Four times

Exercise 2
Step 1
1 of 2
a. The radius can only obtain positive (nonzero) values and thus the domain is $(0,+infty)$. The mass can only take on non-negative values, thus the range is $[0,+infty)$.

b. The function is a good model when $r>0$ (since the radius has to be nonnegative and nonzero).

Result
2 of 2
a. Input $(0,+infty)$, Output $[0,+infty)$

b. $r>0$

Exercise 3
Step 1
1 of 2
No, because the radius can never be zero and the mass (of an object that exists) can also not be zero.
Result
2 of 2
No
Exercise 4
Result
1 of 1
We did not change the function equation, we only changed the domain of the function on which it is defined.

This means that only the part of the graph on the right side of the $y$-axis was used (because the radius is nonnegative).

Exercise 5
Step 1
1 of 2
The maximum or minimum is always attained at the axis of symmetry: $x=-dfrac{b}{2a}$ with $b$ the coefficent of $x$ and $a$ the coefficient of $x^2$. If $a>0$, then the function has a minimum and if $a<0$ then the function has a maximum.

a. Minimum at $x=-dfrac{-2}{2(1)}=1$ (since $f(x)=(x-1)^2=x^2-2x+1$).

b. Minimum at $x=-dfrac{0}{2(1)}=0$

c. Minimum at $x=-dfrac{4}{2(1)}=-2$ (since $f(x)=(x+2)^2=x^2+4x+4$).

d. Maximum at $x=-dfrac{0}{2(-1)}=0$

e. See part (a) to (d)

Result
2 of 2
a. $x=1$

b. $x=0$

c. $x=-2$

d. $x=0$

e. Minima at (a) to (c), Maximum at (d)

Exercise 6
Step 1
1 of 2
If the coefficient is positive, then the graph lies above the $x$-axis (except for at $x=0$). If the coefficient is negative, then the graph lies under the $x$-axis (except for at $x=0$).

Thus the negative coefficient of $x^2$ reflects the graph of $x^2$ about the $x$-axis.

Moreover if the coefficient is smaller than $-1$ then the graph becomes narrower and if the coefficient is greater than $-1$ (and negative), then the graph becomes wider.

Exercise scan

Result
2 of 2
Reflects about $x$-axis
Exercise 7
Step 1
1 of 3
a.Exercise scan
Step 2
2 of 3
b. We ntoe that the graph of $(x-2)^2$ has been translated to the right over 2 units.
Result
3 of 3
Translated to the right over 2 units
Exercise 8
Step 1
1 of 3
a. Add 1 to both sides of the inequality:

$$
6x<12
$$

Divide both sides of the inequality by 6:

$$
x<2
$$

Exercise scan

b. Multiply both sides of the inequality by 3:

$$
xgeq 6
$$

Exercise scan

Step 2
2 of 3
c. Divide both sides of the inequality by 9:

$$
x-2>2
$$

Add 2 to both sides of the inequality:

$$
x>4
$$

Exercise scan

d. Multiply both sides of the inequality by 4:

$$
20-xleq 2
$$

Add $x$ to both sides of the inequality:

$$
20leq 2+x
$$

Subtract 2 from both sides of the inequality:

$$
18leq x
$$

Exercise scan

Result
3 of 3
a. $x4$

d. $xgeq 18$

Exercise 9
Step 1
1 of 3
a. The measure of an interior angle of a regular polygon with $n$ sides is:
$$
dfrac{(n-2)180text{textdegree}}{n}
$$

Thus we then obtain:

$$
dfrac{(n-2)180}{n}=60
$$

Multiply both sides of the equation by $n$:

$$
180n-360=60n
$$

Subtract $60n$ from both sides of the equation:

$$
120n-360=0
$$

Add 360 to both sides of the equation:

$$
120n=360
$$

Divide both sides of the equation by 120:

$$
n=3
$$

b. The measure of an interior angle of a regular polygon with $n$ sides is:
$$
dfrac{(n-2)180text{textdegree}}{n}
$$

Thus we then obtain:

$$
dfrac{(n-2)180}{n}=156
$$

Multiply both sides of the equation by $n$:

$$
180n-360=156n
$$

Subtract $156n$ from both sides of the equation:

$$
24n-360=0
$$

Add 360 to both sides of the equation:

$$
24n=360
$$

Divide both sides of the equation by 24:

$$
n=15
$$

Step 2
2 of 3
c. The measure of an interior angle of a regular polygon with $n$ sides is:
$$
dfrac{(n-2)180text{textdegree}}{n}
$$

Thus we then obtain:

$$
dfrac{(n-2)180}{n}=90
$$

Multiply both sides of the equation by $n$:

$$
180n-360=90n
$$

Subtract $90n$ from both sides of the equation:

$$
90n-360=0
$$

Add 360 to both sides of the equation:

$$
90n=360
$$

Divide both sides of the equation by 90:

$$
n=4
$$

d. The measure of an interior angle of a regular polygon with $n$ sides is:
$$
dfrac{(n-2)180text{textdegree}}{n}
$$

Thus we then obtain:

$$
dfrac{(n-2)180}{n}=140
$$

Multiply both sides of the equation by $n$:

$$
180n-360=140n
$$

Subtract $140n$ from both sides of the equation:

$$
40n-360=0
$$

Add 360 to both sides of the equation:

$$
40n=360
$$

Divide both sides of the equation by 90:

$$
n=9
$$

Result
3 of 3
a. 3
b. 15
c. 4
d. 9
Exercise 10
Step 1
1 of 3
a. On the graph we note that $(6,-6)$ is the intersections of the two lines and thus $(-6,6)$ should be the solution.

Subtract the two equations:

$$
0=-dfrac{5}{2}x+15
$$

Subtract 15 from both sides of the equation:

$$
-15=-dfrac{5}{2}x
$$

Multiply both sides of the equation by $-dfrac{2}{5}$:

$$
6=x
$$

Determine $y$:

$$
y=-2x+6=-2(6)+6=-6
$$

Thus the solution is $(6,-6)$.

Exercise scan

Step 2
2 of 3
b. The two lines are perpendicular, because the product of their slopes is $-1$.
Result
3 of 3
a. $(6,-6)$

b. Perpendicular

Exercise 11
Step 1
1 of 3
a. Not similar, because the ratios of the corresponding sides are not equal:

$$
dfrac{10}{15}=dfrac{12}{18}=1.5neq dfrac{11}{17}
$$

b. The two triangles are similar because of SAS. Dilating the smallest triangle by factor $dfrac{8}{5}$, rotating it 180$text{textdegree}$ and translating it will transform it in the larger triangle.
Step 2
2 of 3
c. The two triangles are similar because of SSS. Dilating, rotating and translating the first triangle will result in the second.
d. The two triangles are similar by SSS, because the ratios of corresponding sides are equal (determine the missing lengths using the Pythagorean theorem):

$$
dfrac{8}{4}=dfrac{6}{3}=dfrac{10}{5}=2
$$

Result
3 of 3
a. Not similar

b. SAS

c. SSS

d. SSS

Exercise 12
Step 1
1 of 2
If the equation of the parabola is $f(x)=ax^2$, then the graph is the graph of $f(x)=x^2$ stretched vertically by factor $a$.

If the equation of the parabola is $f(x)=(bx)^2$, then the graph is the graph of $f(x)=x^2$ stretched horizontally by factor $b$.

If the equation of the parabola is $f(x)=(x-c)^2$, then the graph is the graph of $f(x)=x^2$ translated right by $c$ units (if $c$ is negative, then the translation is to the left by $|c|$ units).

If the equation of the parabola is $f(x)=x^2+d$, then the graph is the graph of $f(x)=x^2$ translated up by $d$ units (if $d$ is negative, then the translation is down by $|d|$ units).

Result
2 of 2
If the equation of the parabola is $f(x)=ax^2$, then the graph is the graph of $f(x)=x^2$ stretched vertically by factor $a$.
Exercise 13
Result
1 of 1
a. If you multiply the equation by a factor $a$ (with $a>1$ and $a$ positive), then the equation becomes $f(x)=ax^2$ and this graph will then be narrower than the graph of $f(x)=x^2$.

b. If you multiply the equation by a factor $a$ (with $a<1$ and $a$ positive), then the equation becomes $f(x)=ax^2$ and this graph will then be wider than the graph of $f(x)=x^2$.

c. If you multiply the equation by a factor $a$ (with $a1$.

Exercise 14
Step 1
1 of 2
If the equation of the parabola is $f(x)=ax^2$, then the graph is the graph of $f(x)=x^2$ stretched vertically by factor $a$. If $a$ is negative, then the graph is also reflected about the $x$-axis.

If the equation of the parabola is $f(x)=(bx)^2$, then the graph is the graph of $f(x)=x^2$ stretched horizontally by factor $b$.

If the equation of the parabola is $f(x)=(x-c)^2$, then the graph is the graph of $f(x)=x^2$ translated right by $c$ units (if $c$ is negative, then the translation is to the left by $|c|$ units).

If the equation of the parabola is $f(x)=x^2+d$, then the graph is the graph of $f(x)=x^2$ translated up by $d$ units (if $d$ is negative, then the translation is down by $|d|$ units).

Thus an equation of the form $f(x)=-a(x+2)^2+6$ with $a<1$ then is the graph of $y=x^2$ vertically compressed, open downward, sifted six units up and shifted two units to the left.

Result
2 of 2
$f(x)=-a(x+2)^2+6$ with $a<1$
Exercise 15
Step 1
1 of 2
If the equation of the parabola is $f(x)=ax^2$, then the graph is the graph of $f(x)=x^2$ stretched vertically by factor $a$. If $a$ is negative, then the graph is also reflected about the $x$-axis.

If the equation of the parabola is $f(x)=(bx)^2$, then the graph is the graph of $f(x)=x^2$ stretched horizontally by factor $b$.

If the equation of the parabola is $f(x)=(x-c)^2$, then the graph is the graph of $f(x)=x^2$ translated right by $c$ units (if $c$ is negative, then the translation is to the left by $|c|$ units).

If the equation of the parabola is $f(x)=x^2+d$, then the graph is the graph of $f(x)=x^2$ translated up by $d$ units (if $d$ is negative, then the translation is down by $|d|$ units).

Result
2 of 2
If the equation of the parabola is $f(x)=ax^2$, then the graph is the graph of $f(x)=x^2$ stretched vertically by factor $a$. If $a$ is negative, then the graph is also reflected about the $x$-axis.
Exercise 16
Step 1
1 of 5
If the equation of the parabola is $f(x)=ax^2$, then the graph is the graph of $f(x)=x^2$ stretched vertically by factor $a$. If $a$ is negative, then the graph is also reflected about the $x$-axis.

If the equation of the parabola is $f(x)=(bx)^2$, then the graph is the graph of $f(x)=x^2$ stretched horizontally by factor $b$.

If the equation of the parabola is $f(x)=(x-c)^2$, then the graph is the graph of $f(x)=x^2$ translated right by $c$ units (if $c$ is negative, then the translation is to the left by $|c|$ units).

If the equation of the parabola is $f(x)=x^2+d$, then the graph is the graph of $f(x)=x^2$ translated up by $d$ units (if $d$ is negative, then the translation is down by $|d|$ units).

Step 2
2 of 5
a. The parabola was shifted down by 4 units and shifted right by 7 units.

$$
y=(x-7)^2-4
$$

Step 3
3 of 5
b. If the vertex is on the $x$-axis at $x=-3$, then the parabola was moved to the left by 3 units.

The parabola was also stretched vertically by a factor of 2.

$$
y=2(x+3)^2
$$

Step 4
4 of 5
c. The parabola opens downward, which implies that the coefficient $a$ needs to be negative. Moreover, a vertical shrink occurred by a factor of 0.5 and thus $a=-0.5$.

The vertex is at $(-5,2)$, which means that the parabola was shifted left by 5 units and shifted up by 2 units.

$$
y=-0.5(x+5)^2+2
$$

Result
5 of 5
a. $y=(x-7)^2-4$

b. $y=2(x+3)^2$

c. $y=-0.5(x+5)^2+2$

Exercise 17
Step 1
1 of 2
a. Replace $x$ with $2$:

$$
(2-1)^2+2=1+2=3
$$

b. Replace $x$ with $-4$:

$$
(-4-1)^2+2=25+2=27
$$

c. Replace $x$ with $-11.3$:

$$
(-11.3-1)^2+2=151.29+2=153.29
$$

Result
2 of 2
a. 3
b. 27
c. 153.29
Exercise 18
Step 1
1 of 3
a. Add 3 to both sides of the inequality:

$$
4xgeq 12
$$

Divide both sides of the inequality by 4:

$$
xgeq 3
$$

Exercise scan

b.Divide both sides of the inequality by 3:

$$
x+4<dfrac{5}{3}
$$

Subtract 4 from both sides of the inequality:

$$
x<-dfrac{7}{4}
$$

Exercise scan

Step 2
2 of 3
c. Multiply both sides of the inequality by 7:

$$
2x<56
$$

Divide both sides of the inequality by 2:

$$
x<28
$$

Exercise scan

d. Use distributive property:

$$
5x+4>-3x+24
$$

Add $3x$ to both sides of the inequality:

$$
8x+4>24
$$

Subtract 4 from both sides of the inequality:

$$
8x>20
$$

Divide both sides of the inequality by 8:

$$
x>dfrac{5}{2}
$$

Exercise scan

Result
3 of 3
a. $xgeq 3$

b. $x<-frac{7}{4}$

c. $xfrac{5}{2}$

Exercise 19
Step 1
1 of 2
If $x=a$ is an $x$-intercept, then the function equation contains tha factor $(x-a)$. We note in the table that $x=-2$ and $x=5$ are the $x$-intercepts, the equation is then of the form:

$$
y=a(x+2)(x-5)
$$

We know that if $x=0$, then $y=-10$:

$$
-10=a(2)(-5)=-10a
$$

Divide both sides of the equation by $-10$:

$$
1=a
$$

Replace $a$ with 1 in the function equation:

$$
y=(x-5)(x+2)
$$

Exercise scan

Result
2 of 2
$$
y=(x-5)(x+2)
$$
Exercise 20
Step 1
1 of 3
a. Subtract the two equations:

$$
y=3-3y+5
$$

Add $3y$ to both sides of the equation:

$$
4y=8
$$

Divide both sides of the equation by 4:

$$
y=2
$$

Determine $x$:

$$
x=3y-5=3(2)-5=1
$$

Thus the solution is $(1,2)$.

Exercise scan

Step 2
2 of 3
b. Add the two equations:

$$
x=-5-2x-4
$$

Add $2x$ to both sides of the equation:

$$
3x=-9
$$

Divide both sides of the equation by 3:

$$
x=-3
$$

Determine $y$:

$$
y=-2x-4=-2(-3)-4=6-4=2
$$

Thus the solutions is $(-3,2)$.

Exercise scan

Result
3 of 3
a. $(1,2)$

b. $(-3,2)$

Exercise 21
Step 1
1 of 2
The circumference of a circle is $C=2pi r$:

$$
102.6=2pi r
$$

Divide both sides of the equation by $2pi$:

$$
16.33approx dfrac{102.6}{2pi}=r
$$

The diameter is twice the radius:

$$
2r=2(16.33)=32.66
$$

Thus the diameter is 32.66ft.

Result
2 of 2
32.66ft
Exercise 22
Step 1
1 of 2
The sum of all angles in a triangle is 180$text{textdegree}$ and vertical angles are congruent:

$$
x=180text{textdegree}-23text{textdegree}-48text{textdegree}=109text{textdegree}
$$

Same-side interior angles of parallel lines and vertical angles are congruent:

$$
y=180text{textdegree}-x=180text{textdegree}-109text{textdegree}=71text{textdegree}
$$

The sum of all angles in a quadrilaterial is 360$text{textdegree}$:

$$
z=360text{textdegree}-81text{textdegree}-x-y=360text{textdegree}-81text{textdegree}-109text{textdegree}-71text{textdegree}=99text{textdegree}
$$

Result
2 of 2
$$
x=109text{textdegree}
$$

$$
y=71text{textdegree}
$$

$$
z=99text{textdegree}
$$

Exercise 23
Step 1
1 of 3
a. The graph of $g$ is the graph of $f$ translated to the right by 3 units and translated down by 4 units.

The vertex of $f$ is $(0,0)$, while the vertex of $g$ is $(3,-4)$.

Exercise scan

Step 2
2 of 3
b. On the graph we note that the $x$-intercepts are $x=1$ and $x=5$, while the $y$-intercept is $y=5$.

c. The equation is standard form is:

$$
g(x)=x^2-6x+9-4=x^2-6x+5
$$

The equation in factored form is then:

$$
g(x)=(x-1)(x-5)
$$

d. The graphing form (the given form) is easier because it immediately tells you the vertex and the roots can be easily determine from it.

e. Because we can read the vertex from the function equation, namely the vertex is $(h,k)$.

Result
3 of 3
a. $(0,0)$, $(3,-4)$

b.

$x$-intercepts: $(1,0)$, $(5,0)$

$y$-intercepts: $(0,5)$

c. $g(x)=(x-1)(x-5)$

d. Graphing form

e. Vertex is $(h,k)$

Exercise 24
Step 1
1 of 2
You can use the complete the square method to rewrite the function in graphing form.

Add and subtract 9 from the given equation:

$$
f(x)=(x^2-6x+9)+5-9
$$

Factorize the perfect square trinomial ($a^2pm 2ab+b^2=(apm b)^2$):

$$
f(x)=(x-3)^2-4
$$

Thus the equation is now in graphing form.

Result
2 of 2
Complete the square
Exercise 25
Step 1
1 of 3
a. Factorize the perfect square trinomial ($a^2pm 2ab+b^2=(apm b)^2$):

$$
f(x)=(x+3)^2
$$

Thus the equation is now in graphing form and the vertex is $(-3,0)$.

Step 2
2 of 3
b. Add 8 and subtract 8 from the function equation:

$$
g(x)=(x^2+6x+9)+1-9
$$

Factorize the perfect square trinomial ($a^2pm 2ab+b^2=(apm b)^2$):

$$
g(x)=(x+3)^2-8
$$

Thus the equation is now in graphing form and the vertex is $(-3,-8)$.

Result
3 of 3
a. $f(x)=(x+3)^2$, $(-3,0)$

b. $g(x)=(x+3)^2-8$, $(-3,-8)$

Exercise 26
Step 1
1 of 6
a. Add and subtract 4 from the function equation:

$$
f(x)=(x^2-4x+4)+3-4
$$

Factorize the perfect square trinomial ($a^2pm 2ab+b^2=(apm b)^2$):

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

Thus the equation is now in graphing form and the vertex is $(-3,0)$.

Step 2
2 of 6
b. Add and subtract 2.25 from the function equation:

$$
g(x)=(x^2-3x+2.25)-5+2.25
$$

Factorize the perfect square trinomial ($a^2pm 2ab+b^2=(apm b)^2$):

$$
g(x)=(x-1.5)^2-2.75
$$

Thus the equation is now in graphing form and the vertex is $(1.5,-2.75)$.

Step 3
3 of 6
c. Add and subtract 32 from the function equation:

$$
j(x)=2(x^2+8x+16)+29-32
$$

Factorize the perfect square trinomial ($a^2pm 2ab+b^2=(apm b)^2$):

$$
j(x)=2(x+4)^2-3
$$

Thus the equation is now in graphing form and the vertex is $(-4,3)$.

Step 4
4 of 6
d. Factorize the perfect square trinomial ($a^2pm 2ab+b^2=(apm b)^2$):

$$
k(x)=-(x+4)^2
$$

Thus the equation is now in graphing form and the vertex is $(-4,0)$.

Step 5
5 of 6
e. All equations have two $x$-intercepts except for the equation in (d) which has only one $x$-intercept.

Exercise scan

Result
6 of 6
a. $f(x)=(x-2)^2-1$

b. $g(x)=(x-1.5)^2-2.75$

c. $j(x)=2(x+4)^2-3$

d. $k(x)=-(x+4)^2$

Exercise 27
Step 1
1 of 2
The mistake was made from step 3 to step 4. She should subtract 18 from both sides of the equation:

$$
4. g(x)+23-18=-2(x^2+6x+9)
$$

Factorize:

$$
5.g(x)+5=-2(x+3)^2
$$

Subtract 5 from both sides of the equation:

$$
6. g(x)=-2(x+3)^2-5
$$

Result
2 of 2
$$
g(x)=-2(x+3)^2-5
$$
Exercise 28
Step 1
1 of 2
Standard form to graphing form

Rewrite the equation using the complete the square method, by adding/subtracting a number such that you get a term of the form $x^2pm 2xb+b^2$, then factorize this into $(xpm b)^2$ to obtain the graphing form.

Result
2 of 2
Rewrite the equation using the complete the square method, by adding/subtracting a number such that you get a term of the form $x^2pm 2xb+b^2$, then factorize this into $(xpm b)^2$ to obtain the graphing form.
Exercise 29
Step 1
1 of 2
We note that the output is the square of the input decreased by 1 and thus the function equation is:

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

Result
2 of 2
$$
f(x)=x^2-1
$$
Exercise 30
Step 1
1 of 3
a. The vertex is $(3,2)$, the function opens downwards because $a=-2<0$ and the graph is vertically stretched by factor 2.

Exercise scan

Step 2
2 of 3
b. Replace $f(x)$ with 0:

$$
0=-2(x-3)^2+2
$$

Subtract 2 from both sides of the equation:

$$
-2=-2(x-3)^2
$$

Divide both sides of the equation by $-2$:

$$
1=(x-3)^2
$$

Take the square root of both sides of the equation:

$$
pm 1 =x-3
$$

Add 3 to both sides of the equation:

$$
4text{ or }2=3pm 1=x
$$

Thus the $x$-intercepts are $x=2$ and $x=4$.

Let $x$ be zero:

$$
f(x)=-2(-3)^2+2=-16
$$

Thus the $y$-intercept is $y=-16$.

Result
3 of 3
a. Vertex $(3,2)$, Opens downwards, Stretched vertically by factor 2

b. $x$-intercepts $(2,0)$ and $(4,0)$, $y$-intercepts $(0,-16)$

Exercise 31
Step 1
1 of 3
If the vertex is $(h,k)$ then the function equation is of the form $f(x)=a(x-h)^2+k$.

a. Replace $h$ with 0 and $k$ with $-5$:

$$
f(x)=ax^2-5
$$

Replace $x$ with $-1$ and $f(x)$ with 2:

$$
2=a(-1)^2-5=a-5
$$

Add 5 to both sides of the equation:

$$
7=a
$$

Replace $a$ in the equation with 7:

$$
f(x)=7x^2-5
$$

$$
text{color{white} jmlirjtet mjretm lijretm lrejtj erjtl jrljtlr jlktjrl jtrlj ljr litelrj tlretm ermthmre hmtlrel thmrleht hlirht lhr}
$$

Step 2
2 of 3
b. Replace $h$ with 1 and $k$ with $4$:

$$
f(x)=a(x-1)^2+4
$$

Replace $x$ with $5$ and $f(x)$ with $-4$:

$$
-4=a(5-1)^2+4=16a+4
$$

Subtract 4 from both sides of the equation:

$$
-8=16a
$$

Divide both sides of the equation by $16$:

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

Replace $a$ in the equation with 7:

$$
f(x)=-dfrac{1}{2}(x-1)^2+4
$$

$$
text{color{white} jmlirjtet mjretm lijretm lrejtj erjtl jrljtlr jlktjrl jtrlj ljr litelrj tlretm ermthmre hmtlrel thmrleht hlirht lhr}
$$

Result
3 of 3
a. $f(x)=7x^2-5$

b. $f(x)=-dfrac{1}{2}(x-1)^2+4$

Exercise 32
Step 1
1 of 2
Let $x$ be the age of Kayla:

$$
x^2+1<65
$$

Subtract 1 from both sides of the inequality:

$$
x^2<64
$$

Since the graph of $f(x)=x^2$ opens upwards:

$$
-8<x<8
$$

Result
2 of 2
$$
-8<x<8
$$
Exercise 33
Step 1
1 of 2
The exterior angle (and also the central angle) is $dfrac{360text{textdegree}}{n}$ with $n$ the number of angles of the regular polygon.

a. Since $n=6$, we exterior angle is:

$$
dfrac{360text{textdegree}}{6}=60text{textdegree}
$$

Since the interior and exterior angle are supplementary, we know that the interior angle is then 120$text{textdegree}$, thus (3).

b. Since $n=6$, we central angle is:

$$
dfrac{360text{textdegree}}{10}=36text{textdegree}
$$

c. Since $n=3$, we exterior angle is:

$$
dfrac{360text{textdegree}}{3}=120text{textdegree}
$$

d. Since $n=4$, we exterior angle is:

$$
dfrac{360text{textdegree}}{4}=90text{textdegree}
$$

Result
2 of 2
a. (3)
b. (1)
c. (4)
d. (2)
Exercise 34
Step 1
1 of 2
Rewrite the rational exponents as roots and the negative exponents as the reciprocal of the base to the positive exponent:

a.
$$
left( dfrac{1}{16}right)^{-1/4}=16^{1/4}=sqrt[4]{16}=sqrt[4]{2^4}=2
$$

b.
$$
x^{-1}y^{-3}=dfrac{1}{x}cdot dfrac{1}{y^3}=dfrac{1}{xy^3}
$$

c.
$$
(25x^4)^{1/2}=sqrt{25x^4}=sqrt{25}cdot sqrt{x^4}=5x^2
$$

Result
2 of 2
a. 2

b. $frac{1}{xy^3}$

c. $5x^2$

Exercise 35
Step 1
1 of 2
Multiply the first equation by 4:

$$
4y=2x-16
$$

$$
x-4y=12
$$

Add the two equations:

$$
x=2x-16+12
$$

Subtract $2x$ from both sides of the equation:

$$
-x=-4
$$

Multiply both sides of the equation by $-1$:

$$
x=4
$$

Determine $y$:

$$
y=dfrac{1}{2}x-4=dfrac{1}{2}(4)-4=2-4=-2
$$

Thus the solution is $(4,-2)$.

Result
2 of 2
D
Exercise 36
Step 1
1 of 3
a.Exercise scan
Step 2
2 of 3
b. If the output is nonnegative, then the input is the same number or the opposite number (same number with different sign). If the output is negative, then the input cannot be determined (because the function cannot give a negative output).
Result
3 of 3
a. 4 or $-4$, 16, $-9$ or 9, Not possible

b. Input is the same number or the opposite number

Exercise 37
Step 1
1 of 2
The absolute value function has a V-shape and consists of two semi-straight lines, one with equation $y=x$ (for $x>0$) and the other with equation $y=-x$ (for $x<0$).

The domain of the function is $mathbb{R}$ and the range contains only nonnegative values $[0,+infty)$.

Exercise scan

Result
2 of 2
The absolute value function has a V-shape and consists of two semi-straight lines, one with equation $y=x$ (for $x>0$) and the other with equation $y=-x$ (for $x<0$).
Exercise 38
Step 1
1 of 2
If the equation of the parabola is $f(x)=a|x|$, then the graph is the graph of $f(x)=|x|$ stretched vertically by factor $a$. If $a$ is negative, then the graph is also reflected about the $x$-axis.

If the equation of the parabola is $f(x)=|bx|$, then the graph is the graph of $f(x)=|x|$ stretched horizontally by factor $b$.

If the equation of the parabola is $f(x)=|x-c|$, then the graph is the graph of $f(x)=|x|$ translated right by $c$ units (if $c$ is negative, then the translation is to the left by $|c|$ units).

If the equation of the parabola is $f(x)=|x|+d$, then the graph is the graph of $f(x)=|x|$ translated up by $d$ units (if $d$ is negative, then the translation is down by $|d|$ units).

Result
2 of 2
If the equation of the parabola is $f(x)=a|x|$, then the graph is the graph of $f(x)=|x|$ stretched vertically by factor $a$. If $a$ is negative, then the graph is also reflected about the $x$-axis.
Exercise 39
Step 1
1 of 2
If the equation of the parabola is $f(x)=a|x|$, then the graph is the graph of $f(x)=|x|$ stretched vertically by factor $a$. If $a$ is negative, then the graph is also reflected about the $x$-axis.

If the equation of the parabola is $f(x)=|bx|$, then the graph is the graph of $f(x)=|x|$ stretched horizontally by factor $b$.

If the equation of the parabola is $f(x)=|x-c|$, then the graph is the graph of $f(x)=|x|$ translated right by $c$ units (if $c$ is negative, then the translation is to the left by $|c|$ units).

If the equation of the parabola is $f(x)=|x|+d$, then the graph is the graph of $f(x)=|x|$ translated up by $d$ units (if $d$ is negative, then the translation is down by $|d|$ units).

We note that the given graph is the graph of the absolute function reflected about the $x$-axis, stretched verticaly by factor 2, translated up by 2 untis and translated right by 1 unit. The equation of the graph is then:

$$
f(x)=-2|x-1|+2
$$

Result
2 of 2
$$
f(x)=-2|x-1|+2
$$
Exercise 40
Step 1
1 of 2
If the equation of the parabola is $f(x)=a|x|$, then the graph is the graph of $f(x)=|x|$ stretched vertically by factor $a$. If $a$ is negative, then the graph is also reflected about the $x$-axis.

If the equation of the parabola is $f(x)=|bx|$, then the graph is the graph of $f(x)=|x|$ stretched horizontally by factor $b$.

If the equation of the parabola is $f(x)=|x-c|$, then the graph is the graph of $f(x)=|x|$ translated right by $c$ units (if $c$ is negative, then the translation is to the left by $|c|$ units).

If the equation of the parabola is $f(x)=|x|+d$, then the graph is the graph of $f(x)=|x|$ translated up by $d$ units (if $d$ is negative, then the translation is down by $|d|$ units).

We note that the given graph is the graph of the absolute function stretched verticaly by factor $dfrac{4}{5}$, translated down by 2 units and translated right by 2 units.

Exercise scan

Result
2 of 2
$$
f(x)=-2|x-1|+2
$$
Exercise 41
Step 1
1 of 2
Transformin an Absolute value function

If the equation of the parabola is $f(x)=a|x|$, then the graph is the graph of $f(x)=|x|$ stretched vertically by factor $a$. If $a$ is negative, then the graph is also reflected about the $x$-axis.

If the equation of the parabola is $f(x)=|bx|$, then the graph is the graph of $f(x)=|x|$ stretched horizontally by factor $b$.

If the equation of the parabola is $f(x)=|x-c|$, then the graph is the graph of $f(x)=|x|$ translated right by $c$ units (if $c$ is negative, then the translation is to the left by $|c|$ units).

If the equation of the parabola is $f(x)=|x|+d$, then the graph is the graph of $f(x)=|x|$ translated up by $d$ units (if $d$ is negative, then the translation is down by $|d|$ units).

Result
2 of 2
If the equation of the parabola is $f(x)=a|x|$, then the graph is the graph of $f(x)=|x|$ stretched vertically by factor $a$. If $a$ is negative, then the graph is also reflected about the $x$-axis.
Exercise 42
Step 1
1 of 2
If the equation of the parabola is $f(x)=a|x|$, then the graph is the graph of $f(x)=|x|$ stretched vertically by factor $a$. If $a$ is negative, then the graph is also reflected about the $x$-axis.

If the equation of the parabola is $f(x)=|bx|$, then the graph is the graph of $f(x)=|x|$ stretched horizontally by factor $b$.

If the equation of the parabola is $f(x)=|x-c|$, then the graph is the graph of $f(x)=|x|$ translated right by $c$ units (if $c$ is negative, then the translation is to the left by $|c|$ units).

If the equation of the parabola is $f(x)=|x|+d$, then the graph is the graph of $f(x)=|x|$ translated up by $d$ units (if $d$ is negative, then the translation is down by $|d|$ units).

Thus the given equation is the graph of the absolute value function translated right by 3 units and down by 1 unit.

Exercise scan

Result
2 of 2
The graph of the absolute value function translated right by 3 units and down by 1 unit.
Exercise 43
Step 1
1 of 2
a. The domain contains all possible $x$-values that the function can take on and thus is $mathbb{R}$.

The range of the function contains all possible $y$-values and thus is $[0,+infty)$.

b. We note that the vertex of $g$ is $(6,3)$ and seems to have stretched by factor 2, thus the equation is then:

$$
g(x)=2(x-6)^2+3
$$

We note that the vertex of $h$ is $(6,3)$ and seems to have stretched by factor $-dfrac{1}{2}$, thus the equation is then:

$$
h(x)=-dfrac{1}{2}(x-6)^2+3
$$

c. The domain contains all possible $x$-values that the function can take on and thus is $mathbb{R}$.

The range of the function contains all possible $y$-values and thus is $[3,+infty)$.

Result
2 of 2
a. $mathbb{R}$, $[0,+infty)$

b. $g(x)=2(x-6)^2+3$, $h(x)=-frac{1}{2}(x-6)^2+3$

c. $mathbb{R}$, $[3,+infty)$

Exercise 44
Step 1
1 of 3
Determine the $x$-intercepts:

Let $f(x)$ be 0:

$$
0=x^2-2x-48
$$

Factorize:

$$
0=(x-8)(x+6)
$$

Zero product property:

$$
x-8=0text{ or }x+6=0
$$

Solve each equation to $x$:

$$
x=8text{ or }x=-6
$$

Determine the $y$-intercept:

Let $x$ be 0:

$$
y=f(x)=0^2-2(0)-48=-48
$$

Step 2
2 of 3
Determine the vertex by rewriting the equation in graphing form:

$$
f(x)=x^2-2x-48
$$

Add and subtract 1 from the equation:

$$
f(x)=(x^2-2x+1)-48-1
$$

Factorize:

$$
f(x)=(x-1)^2-49
$$

Thus the vertex is $(1,-49)$.

Exercise scan
Result
3 of 3
$x$-intercepts: $(8,0)$ and $(-6,0)$

$y$-intercepts: $(0,-48)$

Vertex $(1,-49)$

Exercise 45
Step 1
1 of 2
a. Elian ran 2 miles in 20 minutes, then paused for 10 minutes at the park and then ran back the 2 miles.

b. The speed is the distance covered divided by the time needed (in hours):

$$
dfrac{2}{1/3}=6mph
$$

c. 0 mph, because the slope of the graph is then zero.

d. The speed is the distance covered divided by the time needed (in hours):

$$
dfrac{2}{18/60}=6dfrac{2}{3}mph
$$

Result
2 of 2
a. a. Elian ran 2 miles in 20 minutes, then paused for 10 minutes at the park and then ran back the 2 miles.

b. 6 mph

c. 0 mph

d. $6frac{2}{3}$ mph

Exercise 46
Step 1
1 of 3
Determine the area of the regular hexagon.

A hexagon has 6 vertices. Divide the hexagon into 6 congruent triangles. Determine the the height of these triangles using the sine and cosine ratio:

$$
h=dfrac{3}{sin{60text{textdegree}}}approx 3.46
$$

The area of a triangles is the product of the base and the height divided by 2:

$$
dfrac{6cdot 3.46}{2}=10.38
$$

Since the hexagon is made up out of 6 triangles, the area of the hexagon is:

$$
6cdot 10.38=62.28in^2
$$

Step 2
2 of 3
Determine the area of the circle

$$
A=pi r^2=pi (3.46)^2approx 37.61in^2
$$

The area of the shaded region is the difference in areas:

$$
62.28in^2-37.61in^2=24.67in^2
$$

Result
3 of 3
$$
24.67in^2
$$
Exercise 47
Step 1
1 of 2
Determine the missing side lengths using the Pythagorean theorem:Exercise scan
a. There area is the sum of the bases, multiplied by the height and divided by 2:

$$
A=dfrac{(13+8)4}{2}=42
$$

The perimeter is the sum of the lengths of all sides:

$$
P=13+5+8+2sqrt{5}=26+2sqrt{5}
$$

b. The new area is the previous area are multiplied by the linear scale factor squared:

$$
A=dfrac{1}{3^2}cdot 42=dfrac{14}{3}
$$

The new perimeter is the previous perimeter are multiplied by the linear scale factor:

$$
P=dfrac{1}{3}(26+2sqrt{5})
$$

Result
2 of 2
a. Area 42 and perimeter $26+2sqrt{5}$

b. Area $frac{14}{3}$ and perimeter $frac{1}{3}(26+2sqrt{5})$

Exercise 48
Step 1
1 of 3
Determine the area of the regular hexagon.

A hexagon has 6 vertices. Divide the hexagon into 6 congruent triangles. Determine the the height and base of these triangles using the sine and cosine ratio:

$$
dfrac{b}{2}=3cos{60text{textdegree}}=1.5Rightarrow b=3
$$

$$
h=3sin{60text{textdegree}}approx 2.6
$$

The area of a triangles is the product of the base and the height divided by 2:

$$
dfrac{3cdot 2.6}{2}=3.9
$$

Since the hexagon is made up out of 6 triangles, the area of the hexagon is:

$$
6cdot 3.9=23.4ft^2
$$

Step 2
2 of 3
Determine the area of each rectangle:

$$
A=1cdot 3=3ft^2
$$

The total area is then:

$$
23.4ft^2+6cdot 3ft^2=41.4ft^2
$$

Result
3 of 3
$$
41.4ft^2
$$
Exercise 49
Step 1
1 of 4
a. We note that the $x$-intercepts are $x=50$ and $x=150$, thus the equation is of the form:

$$
y=a(x-50)(x-150)
$$

At $x=0$ we need $y=300$:

$$
300=a(-50)(-150)=7500a
$$

Divide both sides of the equation by 7500:

$$
dfrac{1}{25}=a
$$

Replace $a$ with its value in the equation:

$$
y=dfrac{1}{25}(x-50)(x-150)
$$

Step 2
2 of 4
b. The graph (and thus the roller coaster car) is below ground between 50 and 150 ft.

Thus if

$$
dfrac{1}{25}(x-50)(x-150)<0
$$

we then know that
$$
50<x0
$$

we then know that
$$
x150
$$

Step 3
3 of 4
d.
$$
dfrac{1}{25}(x-50)(x-150)>0
$$

Multiply both sides of the inequality by 25:

$$
(x-50)(x-150)>0
$$

Since the graph of $y=(x-50)(x-150)$ opens upwards:

$$
x150
$$

Result
4 of 4
a. $y=frac{1}{2}(x-50)(x-150)$

b. $50<x<150$

c. $x150$

d. $x150$

Exercise 50
Step 1
1 of 2
a. The net profit is the revnue decreased by the costs:

$$
P(x)=100x(0.05x+5)-300,000=5x^2+500x-300,000
$$

b.
$$
5x^2+500x-300,000<0
$$

Factorize

$$
5(x+300)(x-200)<0
$$

Since the function $y=5(x+300)(x-200)$ opens upwards:

$$
-300<x<200
$$

Thus the park loses money if there are less than 200 visitors.

c.
$$
5x^2+500x-300,000<0
$$

Factorize

$$
5(x+300)(x-200)<0
$$

Since the function $y=5(x+300)(x-200)$ opens upwards:

$$
-300<x<200
$$

d. They are the same because they are solutions of the same inequality. They are different because in (b) you are only interested in $xgeq 0$.

Result
2 of 2
a. $P(x)=5x^2+500x-300,00$

b. Less than 200 visisotrs

c. $-300<x<200$

d. Solutions of same inequality, we are only interested in $xgeq 0$

Exercise 51
Step 1
1 of 3
a.
$$
-16t^2+64t>40
$$

Subtract 40 from both sides of the inequality:

$$
-16t^2+64t-40>0
$$

Determine the roots using the quadratic formula:

$$
t=dfrac{-64pm sqrt{64^2-4(-16)(-40)}}{2(-16)}=2pm dfrac{1}{2}sqrt{6}
$$

Since the function opens downwards, we then know

$$
0.78approx 2- dfrac{1}{2}sqrt{6}<t<2+dfrac{1}{2}sqrt{6}approx 3.22
$$

Exercise scan

Step 2
2 of 3
b. The maximum lies on the axis of symmetry:

$$
x=-dfrac{b}{2a}=-dfrac{64}{2(-16)}=2
$$

The maximum height is then the image:

$$
h(2)=-16(2)^2+64(2)=64
$$

Thus the football reaches the maximum height of 64 ft at 2 s.

Result
3 of 3
a. $0.78<t<3.22$

b. Maximum height of 64 ft at 2 s.

Exercise 52
Step 1
1 of 4
a. Subtract 4 from both sides of the inequality:

$$
x^2+2x-3<0
$$

Factorize:

$$
(x+3)(x-1)<0
$$

Thus the boundary points are $x=-3$ and $x=1$.

Step 2
2 of 4
b. 3 regions: before, between and after the boundary points.Exercise scan
Step 3
3 of 4
c. We note that the region between the two boundary points gives negative values:Exercise scan
Result
4 of 4
a. 2 boundary points

b. 3 regions

c. Region between boundary points

Exercise 53
Step 1
1 of 3
a. Factorize:

$$
(x+4)(x-3)<0
$$

Thus the roots are $x=-4$ and $x=3$. Since the function opens upwards:

$$
-4<x<3
$$

b. Subtract 7 from both sides of the inequality:

$$
-2x^2+10x-7geq 0
$$

Determine the roots using the quadratic formula:

$$
x=dfrac{-10pm sqrt{10^2-4(-2)(-7)}}{2(-2)}=dfrac{5}{2}pm dfrac{1}{2}sqrt{11}
$$

Since the function opens downwards:

$$
dfrac{5}{2}- dfrac{1}{2}sqrt{11}leq xleq dfrac{5}{2}+ dfrac{1}{2}sqrt{11}
$$

Step 2
2 of 3
c. Property absolute value:

$$
x-27
$$

Add 2 to both sides of the inequality:

$$
x9
$$

Result
3 of 3
a. $-4<x<3$

b. $frac{5}{2}-frac{1}{2}sqrt{11}leq xleq frac{5}{2}+frac{1}{2}sqrt{11}$

c. $x9$

Exercise 54
Step 1
1 of 3
a.
$$
5x-7geq 2x+5
$$

Subtract $2x$ from both sides of the inequality:

$$
3x-7geq 5
$$

Add 7 to both sides of the inequality:

$$
3xgeq 12
$$

Divide both sides of the inequality by 3:

$$
xgeq 4
$$

b.
$$
6x-29>4x+12
$$

Subtract $4x$ from both sides of the inequality:

$$
2x-29>12
$$

Add 29 to both sides of the inequality:

$$
2x>41
$$

Divide both sides of the inequality by 41:

$$
x>dfrac{41}{2}
$$

Step 2
2 of 3
c.
$$
x^2leq -4x+5
$$

Add $4x-5$ to both sides of the inequality:

$$
x^2+4x-5leq 0
$$

Factorize:

$$
(x+5)(x-1)leq 0
$$

Thus the roots are $x=-5$ and $x=1$. Since $y=x^2+4x-5$ opens upwards:

$$
-5leq xleq 1
$$

Result
3 of 3
(a) $xgeq 4$

(b) $x>frac{41}{2}$

(c) $-5leq xleq 1$

Exercise 55
Step 1
1 of 2
a. The function increases very rapidly and thus the best type of function is exponential.

b. Since the increase is constant, the best type of function is linear.

c. The apple will travel an arc in the shape of a parabola and thus a quadratic function is best.

Result
2 of 2
a. Exponential
b. Linear
c. Quadratic
Exercise 56
Step 1
1 of 2
There is no difference between the graphs or tables, because the functions are the same (and since $y=f(x)$).
Result
2 of 2
No difference, Same function
Exercise 57
Step 1
1 of 2
a. Add and Subtract 9 from the equation:

$$
y=(x^2+6x+9)+15-9
$$

Factorize the perfect square trinomial ($a^2pm 2ab+b^2=(apm b)^2$):

$$
f(x)=(x+3)^2+6
$$

Thus the equation is now in graphing form with vertex $(-3,6)$ and from the original equation we note that $y=15$ is the $y$-intercept.

b. Add and Subtract 2.25 from the equation:

$$
y=(x^2-3x+2.25)+9-2.25
$$

Factorize the perfect square trinomial ($a^2pm 2ab+b^2=(apm b)^2$):

$$
f(x)=(x-1.5)^2+6.75
$$

Thus the equation is now in graphing form with vertex $(1.5,6.75)$ and from the original equation we note that $y=9$ is the $y$-intercept.

Result
2 of 2
a. $(-3,6)$, $y=15$

b. $(1.5,6.75)$, $y=9$

Exercise 58
Step 1
1 of 4
**Concept**
We take note that the properties of a triangle’s circumcenter are as follows:
1. The circumcenter is the center of the circumcircle
2. All the vertices of a triangle are ​equidistance from the circumcenter
3. In an obtuse-angled triangle, the circumcenter lies outside of the triangle
4. In an acute-angle triangle, the circumcenter is inside of the triangle
5. In a right-angle triangle, the circumcenter is at the midpoint of the hypotenuse side of the triangle
Step 2
2 of 4
**Given**
The diagram of the $bigtriangleup$ XYZ is as follows:
![‘slader’](https://slader-solution-uploads.s3.amazonaws.com/44e565de-7813-487e-85a3-04258138b57b-1626601115881707.png)

We are to determine which point is the circumcenter of the triangle

Step 3
3 of 4
**Solution**
We first determine what kind of triangle $bigtriangleup$ XYZ is. We can observe that $bigtriangleup$ XYZ is an obtuse-angled triangle, hence, from the property of the triangle’s circumcenter, we note that we can locate the circumcenter of this triangle outside of the triangle. Hence, point A cannot be a circumcenter.
Step 4
4 of 4
Next, we take note that all of the vertices of the triangle are equidistant to the circumcenter. Since point C is closer to the vertices X and Y and far from vertex Z, point C cannot be a circumcenter of the triangle. Hence, assuming that point B is the center of the circumcircle and is equidistant from all the vertices of the triangle. Therefore, point B can be a possible circumcenter of $bigtriangleup$ XYZ.
Exercise 59
Step 1
1 of 3
a. Multiply the second equation by 3:

$$
3x-y=14
$$

$$
3x=6y+24
$$

Subtract the two equations:

$$
-y=-6y-10
$$

Add $6y$ to both sides of the equation:

$$
5y=-10
$$

Divide both sides of the equation by 5:

$$
y=-2
$$

Determine $x$:

$$
x=2(-2)+8=-4+8=4
$$

Thus the solution is $(4,-2)$.

b. Subtract the two equations:

$$
0=3y+12
$$

Subtract 12 from both sides of the equation:

$$
-12=3y
$$

Divide both sides of the equation by 3:

$$
-4=y
$$

Determine $x$:

$$
x=2y+2=2(-4)+2=-8+2=-6
$$

Thus the solution is $(-6,-4)$.

Step 2
2 of 3
c. Add the two equations:

$$
18x=9
$$

Divide both sides of the equation by 18:

$$
x=dfrac{1}{2}
$$

Determine $y$:

$$
y=13-2x=13-1=12
$$

Thus the solution is $left(dfrac{1}{2},12right)$

Result
3 of 3
a. $(4,-2)$

b. $(-6,-4)$

c. $left(frac{1}{2},12right)$

Exercise 60
Step 1
1 of 2
a. The midpoint of a line segment with end points $(x_1,y_1)$ and $(x_2,y_2)$ is:

$$
left( dfrac{x_1+y_1}{2}, dfrac{x_2+y_2}{2}right)
$$

Thus we then obtain:

$$
D=left( dfrac{1-1}{2}, dfrac{9-1}{2}right)=(0,4)
$$

$$
E=left( dfrac{7+1}{2}, dfrac{5+9}{2}right)=(4,7)
$$

b. Determine the length using the distance formula $sqrt{(x_2-x_1)^2+(y_2-y_1)^2}$:

$$
DE=sqrt{(4-0)^2+(7-4)^2}=sqrt{25}=5
$$

$AC$ will be twice $DE$ and thus will be 10 (since $overline{DE}$ is the median).

c.
$$
AC=sqrt{(7+1)^2+(5+1)^2}=sqrt{100}=10
$$

d. $F$ is the middle of $overline{BD}$:

$$
F=left( dfrac{0+1}{2}, dfrac{4+9}{2}right)=(0.5,6.5)
$$

$G$ is the middle of $overline{BE}$:

$$
G=left( dfrac{1+4}{2}, dfrac{9+7}{2}right)=(2.5,8)
$$

$overline{FG}$ is then twice as long as $overline{DE}$ and thus is four times as long as $overline{AC}$.

Exercise scan

Result
2 of 2
a. $(0,4)$, $(4,7)$

b. 5, 10

c. 10

d. $(0.5,6.5)$, $(2.5,8)$

Exercise 61
Step 1
1 of 3
a.Exercise scan
Step 2
2 of 3
b. We note on the graph that the two graphs intersect twice.

c. The points of intersection are about $(-2.5,3)$ and $(2,-8)$.

Result
3 of 3
a. Graph

b. Twice

c. $(-2.5,3)$ and $(2,-8)$

Exercise 62
Step 1
1 of 2
a. We have used the method of elimination and the method of substitution.

b. Subtract the two equations:

$$
0=x^2+0.5x-5
$$

Factorize:

$$
0=0.5(x-2)(2x+5)
$$

Zero product property:

$$
x-2=0text{ or }2x+5=0
$$

Solve each equation to $x$:

$$
x=2text{ or }2x=-5
$$

$$
x=2text{ or }x=-dfrac{5}{2}=-2.5
$$

Determine $y$:

$$
y=-2.5(2)-3=-5-3=-8
$$

$$
y=-2.5left( -dfrac{5}{2}right)-3=6.25-3=3.25
$$

Thus the solutions are $(2,-8)$ and $(-2.5,3.25)$.

Result
2 of 2
a. Method of elimination, Method of substitution

b. $(2,-8)$ and $(-2.5,3.25)$

Exercise 63
Step 1
1 of 3
a. The graphs do not have any points of intersection.Exercise scan
Step 2
2 of 3
b. Subtract the two equations:

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

Determine the solution using the quadratic formula:

$$
x=dfrac{2pm sqrt{(-2)^2-4(1)(5)}}{2(1)}=dfrac{2pm sqrt{-16}}{2}=dfrac{2pm 4i}{2}=1pm 2i
$$

Determine $y$:

$$
y=2x-5=2(1pm 2i)-5=2pm 4i-5=-3pm 4i
$$

Thus the note that the solutions are complex. This relates to (a) because complex solutions are not shown on a set of real axis.

Result
3 of 3
a. 0 points of intersection

b. $(1pm 2i, -3pm 4i)$

Exercise 64
Step 1
1 of 8
If the system has two real solutions, then the graphs intersect twice. If the system has one real solution, then the graphs intersect once. If the system has two complex solutions, then the graphs do not intersect.
Step 2
2 of 8
(a)
$$
y=x^2
$$

$$
y=2x-1
$$

Subtract the two equations:

$$
0=x^2-2x+1
$$

Factorize:

$$
0=(x-1)^2
$$

Zero product property:

$$
0=x-1
$$

Add 1 to both sides of the equation:

$$
1=x
$$

Determine $y$:

$$
y=x^2=(1)^2=1
$$

Thus the note that the system has one real solution $(1,1)$. This relates to the graph because the graphs will have one intersection.

Exercise scan

Step 3
3 of 8
(b)

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

The left-side of the two equations is the same expression and thus the right-sides of the equations need to be equal.

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

Add $x^2$ to each side:

$$
2x^2-5x+6=0
$$

Determine roots of quadratic equation $ax^2+bx+c=0$ using the quadratic formula $x=frac{-bpm sqrt{b^2-4ac}}{2a}$

$$
begin{align*}
x&=frac{-(-5)pm sqrt{(-5)^2-4(2)(6)}}{2(2)}=frac{5pm sqrt{-23}}{4}
end{align*}
$$

However, we now note that we take the square root of a negative integer, which is not possible and thus there are no real solutions. This then indicates that there are no intersections between the two graphs.

This relates to the graph because the graphs will have no intersections.

Exercise scan

Step 4
4 of 8
(c)
$$
begin{align*}
y&=x^2-4x+5
\ y&=-x^2+4x-1
end{align*}
$$

Subtract the two equations:

$$
0=2x^2-8x+6
$$

Use distributive property:

$$
0=2(x^2-4x+3)
$$

Factorize:

$$
0=2(x-3)(x-1)
$$

Zero product property:

$$
0=x-3text{ or }0=x-1
$$

Solve each equation to $x$:

$$
x=3text{ or }x=1
$$

Determine corresponding $y$-values:

$$
begin{align*}
y&=x^2-4x+5=3^2-4(3)+5=2
\ y&=x^2-4x+5=1^2-4(1)+5=2
end{align*}
$$

Thus the note that the system has two real solutions $(3,2)$ and $(1,2)$. This relates to the graph because the graphs will have two intersections.

Exercise scan

Step 5
5 of 8
(d)

$$
begin{align*}
y&=x^2-x-2
\ y&=x^2+2x+1
end{align*}
$$

Subtract the two equations:

$$
0=-3x-3
$$

Factorize:

$$
0=-3(x+1)
$$

Zero product property:

$$
0=x+1
$$

Subtract 1 from both sides of the equation:

$$
-1=x
$$

Determine $y$:

$$
y=x^2-x-2=(-1)^2-(-1)-2=1+1-2=0
$$

Thus the note that the system has one real solution $(-1,0)$. This relates to the graph because the graphs will have one intersection.

Exercise scan

Step 6
6 of 8
(e)
$$
begin{align*}
y&=x^2-x-2
\ y&=x-6
end{align*}
$$

The left-side of the two equations is the same expression and thus the right-sides of the equations need to be equal.

$$
x^2-x-2=x-6
$$

Subtract $x$ from each side:

$$
x^2-2x-2=-6
$$

Add $6$ to each side:

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

Determine roots of quadratic equation $ax^2+bx+c=0$ using the quadratic formula $x=frac{-bpm sqrt{b^2-4ac}}{2a}$

$$
begin{align*}
x&=frac{-(-2)pm sqrt{(-2)^2-4(1)(4)}}{2(1)}=frac{2pm sqrt{-12}}{2}
end{align*}
$$

However, we now note that we take the square root of a negative integer, which is not possible and thus there are no real solutions. This then indicates that there are no intersections between the two graphs.

This relates to the graph because the graphs will have no intersections.

Exercise scan

Step 7
7 of 8
(f)

$$
begin{align*}
y&=2x^2+3x-9
\ y&=x-5
end{align*}
$$

Subtract the two equations:

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

Use distributive property:

$$
0=2(x^2+x-2)
$$

Factorize:

$$
0=2(x-1)(x+2)
$$

Zero product property:

$$
0=x-1text{ or }0=x+2
$$

Solve each equation to $x$:

$$
x=1text{ or }x=-2
$$

Determine corresponding $y$-values:

$$
begin{align*}
y&=x-5=1-5=-4
\ y&=x-5=-2-5=-7
end{align*}
$$

Thus the note that the system has two real solutions $(1,-4)$ and $(-2,-7)$. This relates to the graph because the graphs will have two intersections.

Exercise scan

Result
8 of 8
If the system has two real solutions, then the graphs intersect twice. If the system has one real solution, then the graphs intersect once. If the system has two complex solutions, then the graphs do not intersect.

(a) One intersection $(1,1)$

(b) No intersection

(c) Two intersections $(3,2)$ and $(1,2)$

(d) One intersection $(-1,0)$

(e) No intersections

(f) Two intersections $(1,-4)$ and $(-2,-7)$

Exercise 65
Step 1
1 of 2
a. The graphs seem to have one point of intersection.

b. Subtract the two equations:

$$
0=2x^2-dfrac{17}{3}x+4
$$

Multiply both sides of the equation by 3:

$$
0=6x^2-17x+18
$$

Determine the roots using the quadratic formula:

$$
x=dfrac{17pm sqrt{(-17)^2-4(6)(18)}}{2(6)}=dfrac{17pm sqrt{-143}}{12}=dfrac{17pm sqrt{143}i}{12}
$$

Thus the note that the solutions are complex and thus the graphs do not intersect.

Result
2 of 2
a One point of intersection

b. No intersection

Exercise 66
Step 1
1 of 5
a.Exercise scan
b.Exercise scan
Step 2
2 of 5
c. Does not exist, because a line and a parabola always intersect 0, 1 or 2 times.
d.Exercise scan
Step 3
3 of 5
e.Exercise scan
f.Exercise scan
Step 4
4 of 5
g.Exercise scan
Result
5 of 5
Graph in (c) is not possible
Exercise 67
Step 1
1 of 2
Subtract the two equations:

$$
0=x^2+4x+3
$$

Factorize:

$$
0=(x+3)(x+1)
$$

Zero product property:

$$
x+3=0text{ or }x+1=0
$$

Solve each equation to $x$:

$$
x=-3text{ or }x=-1
$$

Determine $y$:

$$
y=x+5=-3+5=2
$$

$$
y=x+5=-1+5=4
$$

Thus the solutions are $(-3,2)$ and $(-1,4)$.

Exercise scan

Result
2 of 2
$(-3,2)$ and $(-1,4)$
Exercise 68
Step 1
1 of 2
a. Eliana was fastest during the 30-40 minute interval, because the increase in distance is the greatest on this interval. Eliana was slowest during the 10-20 minute interval, because the increase in distance is the least on this interval.

b. The average speed is the difference in distance divided by the distance in time (in hours):

$$
dfrac{4.8-3.7}{5/6-4/6}=dfrac{1.1}{1/6}=6.6mph
$$

Result
2 of 2
a. 30-40 minute interval, 10-20 minutes interval

b. 6.6 mph

Exercise 69
Step 1
1 of 2
If the function equation is of the form $f(x)=a(x-h)^2+k$, then the vertex is $(h,k)$.

a. $(-3.5,10.25)$

b. $(-1,1)$

c. $(2.5,0.75)$

Result
2 of 2
a. $(-3.5,10.25)$

b. $(-1,1)$

c. $(2.5,0.75)$

Exercise 70
Step 1
1 of 1
$$
mangle ECB=mangle EAD (text{Given})
$$

$$
overline{AE}cong overline{EC} (Etext{ is the midpoint of} overline{AC})
$$

$$
mangle AED=mangle BEC (text{Vertical angles})
$$

$$
Downarrow SAS
$$

$$
triangle AEDcong triangle CEB
$$

$$
Downarrow
$$

$$
overline{AD}cong overline{CB}
$$

Exercise 71
Step 1
1 of 2
Determine the height of the parallelogram using the sine ratio:

$$
h=12sin{60text{textdegree}}approx 10.39
$$

The area of a parallelogram is the product of the length and the height:

$$
A_p=15cdot 10.39=155.85in^2
$$

The area of a circle sector with center angle $theta$ is $dfrac{theta}{360text{textdegree}}pi r^2$:

$$
A_c=dfrac{60text{textdegree}}{360text{textdegree}}pi 12^2=24piapprox 75.40in^2
$$

Thus the total area is then:

$$
A=A_p+A_c=155.85in^2+75.40in^2=231.25in^2
$$

The arc lengths of a sector with center angle $theta$ is $dfrac{theta}{360text{textdegree}}2pi r$:

$$
C=dfrac{60text{textdegree}}{360text{textdegree}}2pi 12=4pi
$$

The perimeter is then the sum of all lengths of the sides:

$$
15+12+15+12+4pi=54+4pi approx 66.57 in
$$

Result
2 of 2
Area 231.25 in$^2$

Perimeter 66.57 in

Exercise 72
Step 1
1 of 2
a. Use the addition rule:

$$
P(AorUnder 20)=P(A)+P(Under20)-P(AandUnder20)
$$

$$
=dfrac{152+107+78+34}{1000}+dfrac{152+40+44}{1000}-dfrac{152}{1000}=dfrac{455}{1000}=0.455=45.5%
$$

b. The probability of an event not happening is 100% decreased by the probability of the event happening:

$$
P(notAandNotUnder 20)=100%-P(AorUnder 20)=100%-45.5%=54.5%
$$

c. The probability of an event not happening is 100% decreased by the probability of the event happening:

$$
begin{align*}
P(20orOlder)&=100%-P(Under20)
\ &=100%-dfrac{152+40+44}{1000}
\ &=100%-dfrac{236}{1000}
\ &=100%-23.6%
\ &=76.4%
end{align*}
$$

d. The probability is the number of favorable outcomes divided by the number of possible outcomes:

$$
P(AGivenUnder 20)=dfrac{152}{250}=0.608=60.8%
$$

Result
2 of 2
a. 45.5%

b. 54.5%

c. 76.4%

d. 60.8%

Exercise 73
Step 1
1 of 3
a. The shape of the curve is a parabola, just as you could expect.Exercise scan
Step 2
2 of 3
b.
$$
dfrac{Delta y}{Delta x}=dfrac{60.3-34.2}{1-0.5}=52.2
$$

Thus the average rate of change is 52.2 ft per second.

c. The velocity is the distance traveled divided by the time:

$$
dfrac{88.4-78.4}{2-1}=10ft/s
$$

d. The maximum height is about 90.5ft. The velocity is the distance traveled divided by the time:

$$
dfrac{84.6-88.4}{3-2}approx -3.8 ft/s
$$

e. At about 2.5 seconds, yes because this is about half the time it takes for the balloon to land on the ground again.

f. The velocity is the distance traveled divided by the time:

$$
dfrac{0-18.8}{4.8-4.5}approx -63ft/s
$$

Result
3 of 3
a. Parabola

b. 52.2 ft per second

c. 10 ft/s

d. $-3.8$ ft/s

e. At about 2.5 seconds

f. $-63$ ft/s

Exercise 74
Step 1
1 of 2
The average rate of change is the difference between the height divided by the difference in time:

a.
$$
dfrac{96-90}{2.5-1.875}=9.6ft/s
$$

b.
$$
dfrac{90-90}{3.125-1.875}=0ft/s
$$

c.
$$
dfrac{42-72}{4.375-3.75}=-48ft/s
$$

d.
$$
dfrac{42-0}{0.625-0}=67.2ft/s
$$

e. The height is increasing before the maximum and thus at less than 2.5s. The height is decreasing after the maximum and thus at more than 2.5s.

Result
2 of 2
a. 9.6 ft/s

b. 0 ft/s

c. $-48$ ft/s

d. 67.2 ft/s

c. Increasing at less than 2.5 s, Decreasing at more than 2.5 s.

Exercise 75
Step 1
1 of 3
If the vertex is $(h,k)$ then the function equation is of the form $f(x)=a(x-h)^2+k$. The roots are also symmetric in regards to the axis of symmetry (on which the vertex lies).

Replace $h$ with 2.25 and $k$ with $81$:

$$
f(x)=a(x-2.25)^2+81
$$

Replace $x$ with $4.5$ and $f(x)$ with $0$:

$$
0=a(4.5-2.25)^2+81=5.0625a+81
$$

Subtract 81 from both sides of the equation:

$$
-81=5.0625a
$$

Divide both sides of the equation by $5.0625$:

$$
-16=-dfrac{81}{5.0625}=a
$$

Replace $a$ in the equation with $-16$:

$$
f(x)=-16(x-2.25)^2+81
$$

Step 2
2 of 3
Evaluate the function at $x=0.5$:

$$
f(0.5)=-16(0.5-2.25)^2+81=32
$$

The average rate of change is the change in distance divided by the change:

$$
dfrac{32-0}{0.5-0}=64ft/s
$$

Result
3 of 3
$$
f(x)=-16(x-2.25)^2+81
$$

64 ft/s

Exercise 76
Step 1
1 of 9
**Concept**
The equation of motion of the projectile can be described by the following:
$$begin{gather}
f(x) = a(x-h)^2 + k
end{gather}$$
Step 2
2 of 9
**Given**
Since Char used Al’s slingshot, the equation of Char’s launch will be similar to Al’s. From Problem 9-75, we observe that the equation of motion of Al’s launch is described by the equation: $f(x) = -16(x-2.25)^2 + 81$.

However, in Char’s launch, he launched the balloon at a height $15 text{ ft}$. Hence, the maximum height of the balloon will change.

Step 3
3 of 9
**Part a**
Since Char used Al’s slingshot, we use the equation of motion of Al’s launch. However, we increase the maximum height of the launch since Char initially launched the balloon from the top of the bleachers. We obtain the maximum height of the launch as follows:
$$begin{aligned}
k &= k_i + Delta k \
&= 81 + 15 \
&= boxed{96 text{ ft}}
end{aligned}$$

Step 4
4 of 9
We know that the balloon is initially launched at a height $15 text{ ft}$, hence, at $x=0$, the height of the balloon must be equal to $15$. Using for the value of $k$, we calculate for the value of $h$ as follows:
$$begin{aligned}
-16(x-h)^2 + k &=15 \
-16(0-h)^2 + (81 + 15) &= 15 \
-16(0-h)^2 + 96 &= 15 \
-16 h^2 + &= -81 \
h^2 &= frac{-81}{-16} \
h^2 &= 5.0625 \
h &= sqrt{5.0625} \
& boxed{h = 2.25}
end{aligned}$$

Hence, the time will not change for Char’s launch.

Step 5
5 of 9
Using the value of $h$ and change in value and $k$, we obtain the equation of motion of Char’s balloon as follows:
$$begin{aligned}
f(x) &= a(x-h)^2 + k \
& h = 2.25 \
& k = 96 \
f(x) &= -16(x-h)^2 + k \
f(x) &= -16(x-2.25)^2 + 96
end{aligned}$$

Hence, the equation of Char’s launch will be described by the function: $boxed{f(x) = -16(x-2.25)^2 +96}$

Step 6
6 of 9
**Part b**
We obtain the time period where the height of Char’s balloon to be increasing using the equation of motion of Char’s launch. Since we know that the maximum height of the launch is $96 text{ ft}$, we know that the height is increasing at a time wherein the height of the launch is less than the maximum height and when the time is less than the value of $h$.
Step 7
7 of 9
To obtain the time periods by using test points. We obtain the position of the balloon at $x=2.25$ using the equation of the balloon’s motion as follows:
$$begin{aligned}
f(x) &= -16(x-2.25)^2 +96 \
x &= 2.25 \
f(x) &= -16(2.25-2.25)^2 +96 \
f(x) &= 96
end{aligned}$$

We observe that at time $t=2.25 text{ s}$, the maximum height is reached by the balloon. After this point, the balloon will then travel downwards. Hence, at time $t=0 text{ s}$ to $t=2.25 text{ s}$, the height of Char’s balloon is increasing. The height of Char’s balloon increases at $boxed{0 text{ s} < x le 2.25 text{ s}}$

Step 8
8 of 9
**Part c**
We then determine the time period of when the height of Char’s balloon is decreasing. Since we know that the the maximum height is reached when the balloon is at a time $t=2.25 text{ s}$, after this height is reached the balloon will then travel downward, hence, the balloon height will be decreasing after this time. Therefore, the height of Char’s balloon decreases at $boxed{2.25 text{ s} < x le 4.5 text{ s}}$
Result
9 of 9
a. $f(x) = -16(x-2.25)^2 + 96$
b. $text{increasing at } 0 le x le 2.25 text{ s}$
c. $text{decreasing at } 2.25 text{ s} < x le 4.5 text{ s}$
Exercise 77
Step 1
1 of 11
**Concept**
The general equation for projectile motion is given by the equation:
$$begin{gather}
f(t) = frac{1}{2}at^2 + v_o t + h_o
end{gather}$$
Step 2
2 of 11
**Given**
Al’s balloon equation of motion: $f(x) = -16(t-2.25)^2 + 81$
Char’s balloon equation of motion: $f(x) = -16(t-2.25)^2 + 96$
$a = g$

Obtain (a) Al’s equation in standard form, (b) Char’s equation in standard form, and (c) determine what the coefficients represent

Step 3
3 of 11
**Part a**
We know that the general equation for the projectile motion is described by Eq (1). Using Al’s equation we determine its standard form as follows:
$$begin{aligned}
f(t) &= -16(t-2.25)^2 +81 \
&= -16(t^2 -4.5t+5.0625) + 81 \
&= -16t^2 +(-16 cdot -4.5t) + (-16 cdot 5.0625) + 81 \
&= -16t^2 +72t -81 + 81 \
&= boxed{-16t^2 + 72t}
end{aligned}$$
Step 4
4 of 11
We determine the values of $v_o$ and $h_o$ to verify Al’s equation. The initial velocity can be obtained by getting the derivative with respect to time of the equation of motion and when $t=0$. We obtain the value of the initial velocity as follows:
$$begin{aligned}
v(t) &= frac{d}{dt}f(t) \
v(t) &= frac{d}{dt}(-16(t-2.25)^2 + 81) \
v(t) &= -32(t-2.25) \
v(0) &= -32(0-2.25) \
&= boxed{72 frac{text{ft}}{text{s}}}
end{aligned}$$
Step 5
5 of 11
Next, we determine the initial height. We obtain it using the equation of motion at $t=0$. We calculate for the initial height as follows:
$$begin{aligned}
f(t) &= -16(t-2.25)^2 + 81 \
h(t) &= -16(t-2.25)^2 + 81 \
h(0) &= -16(0-2.25)^2 + 81 \
&= boxed{0 text{ ft}}
end{aligned}$$
Step 6
6 of 11
We obtain the standard form of Al’s equation using the value of $g$, $v_o$, and $h_o$ as follows:
$$begin{aligned}
f(t) &= frac{1}{2}at^2 + v_o t + h_o \
&= frac{1}{2}gt^2 + 72t + 0 \
&= frac{1}{2}gt^2 + 72t
end{aligned}$$

We verify that Al’s equation in standard form is: $boxed{-16t^2 + 72t}$

Step 7
7 of 11
**Part b**
We know that the general equation for the projectile motion is described by Eq (1). Using Char’s equation we determine its standard form as follows:
$$begin{aligned}
f(t) &= -16(t-2.25)^2 +96 \
&= -16(t^2 -4.5t+5.0625) + 96 \
&= -16t^2 +(-16 cdot -4.5t) + (-16 cdot 5.0625) + 96 \
&= -16t^2 +72t -81 + 96 \
&= boxed{-16t^2 + 72t+15}
end{aligned}$$
Step 8
8 of 11
Again, we need to determine the value of $v_o$ and $h_o$ using the Char’s equation of motion. We obtain the value of the initial velocity as follows:
$$begin{aligned}
v(t) &= frac{d}{dt}f(t) \
v(t) &= frac{d}{dt}(-16(t-2.25)^2 + 96) \
v(t) &= -32(t-2.25) \
v(0) &= -32(0-2.25) \
&= boxed{72 frac{text{ft}}{text{s}}}
end{aligned}$$
Step 9
9 of 11
Next, we determine the initial height. We obtain it using the equation of motion at $t=0$. We calculate for the initial height as follows:
$$begin{aligned}
f(t) &= -16(t-2.25)^2 + 96 \
h(t) &= -16(t-2.25)^2 + 96 \
h(0) &= -16(0-2.25)^2 + 96 \
&= boxed{15 text{ ft}}
end{aligned}$$
Step 10
10 of 11
We obtain the standard form of Char’s equation using the value of $g$, $v_o$, and $h_o$ as follows:
$$begin{aligned}
f(t) &= frac{1}{2}at^2 + v_o t + h_o \
&= frac{1}{2}gt^2 + 72t + 15 \
&= frac{1}{2}gt^2 + 72t +15
end{aligned}$$

We verify that Char’s equation in standard form is: $boxed{-16t^2 + 72t+15}$

Step 11
11 of 11
**Part c**
Based on the the general equation for the projectile motion, the coefficients of the equations of motion of Al’s and Char’s balloons, represents the value of $frac{1}{2}g$, the initial velocity, and the initial height of the projectile.
Exercise 78
Step 1
1 of 2
The average rate of change is the difference between the height divided by the difference in time:

a.
$$
dfrac{12-7}{0.5-0.25}=20ft/s
$$

b.
$$
dfrac{16-12}{1-0.5}=8ft/s
$$

c. The velocity appears to become zero, this makes sense because the velocity changes sign after the top of her jump (after the top the velocity will be negative, while before it was positive, this is because the velocity changes direction).

Result
2 of 2
a. 20 ft/s

b. 8 ft/s

c. Become zero

Exercise 79
Step 1
1 of 2
A graph is the graph of the function if every vertical line that you can draw intersects the graph at most once.

a. Function
b. Not a function
c. Function
d. Not a function
e. Yes, (a) is a constant function, because the function always takes on the value 2 no matter the input.

Result
2 of 2
a. Function
b. Not a function
c. Function
d. Not a function
e. Yes, (a)
Exercise 80
Step 1
1 of 2
a. Rotating a point about the origin 180$text{textdegree}$, interchanges its $x$- and $y$-coordinates, thus we then obtain:

$$
A’=(-1,-2)
$$

b. Reflecting a point about the $x$-axis, changes the sign of the $y$-coordinate and thus we obtain:

$$
C’=(4,-4)
$$

c. Apply the same transformation to the coordinates of $B$:

$$
B’=(4-1,1+3)=(3,4)
$$

Result
2 of 2
a. $(-1,-2)$

b. $(4,-4)$

c. $(3,4)$

Exercise 81
Step 1
1 of 2
a. The given transformation translates the function down by 2 units:

$$
a(x)=f(x)-2=x^2-2
$$

b. The given transformation reflects the function about the $x$-axis and stretches the function vertically by factor 2:

$$
b(x)=-2f(x)=-2x^2
$$

c. The given transformation translates the function to the right by 2 units:

$$
c(x)=f(x-2)=(x-2)^2
$$

d. The given transformation stretches the function horizontally by factor $dfrac{1}{2}$.

$$
d(x)=f(2x)=(2x)^2=4x^2
$$

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

b. $b(x)=-2x^2$

c. $c(x)=(x-2)^2$

d. $d(x)=4x^2$

Exercise 82
Step 1
1 of 2
If the function equation is of the form $f(x)=a(x-h)^2+k$ then the vertex is $(h,k)$.

a. The vertex is $(2,6)$ and this vertex represents the maximum value, because $a=-2$ is negative and thus the function opens downwards.

b.

Exercise scan

Result
2 of 2
$(2,6)$, Maximum
Exercise 83
Step 1
1 of 2
a. The interior and exterior angle of a polygon are supplementary. Thus the interior angle is:

$$
180text{textdegree}-29text{textdegree}=151text{textdegree}
$$

b. The interior angle of a polygon with $n$ sides is $dfrac{n-2}{n}180text{textdegree}$ and thus let:

$$
dfrac{n-2}{n}180text{textdegree}=170text{textdegree}
$$

Multiply both sides of the equation by $n$:

$$
(n-2)180=170n
$$

Divide both sides of the equation by 180:

$$
n-2=dfrac{17}{18}
$$

Add 2 to both sides of the equation:

$$
n=dfrac{53}{18}
$$

Since $n$ is not an integer, the regular polygon does not exist.

c. The sum of the interior angles of a regular $n$-gon is $(n-2)180text{textdegree}$ and thus we obtain for the 29-gon:

$$
(29-2)180text{textdegree}=27cdot 180text{textdegree}=4,860text{textdegree}
$$

Result
2 of 2
a. 151$text{textdegree}$

b. No

c. 4,860$text{textdegree}$

Exercise 84
Step 1
1 of 2
The expected number of times it will land in each region is the product of the number of spins and the probability of the region:

$$
A: 80cdot dfrac{1}{4}=20
$$

$$
B: 80cdot dfrac{3}{8}=30
$$

$$
C: 80cdot dfrac{3}{8}=30
$$

Thus we expect to land on A 20 times and on B and C 30 times each.

Result
2 of 2
A: 20 times

B: 30 times

C: 30 times

Exercise 85
Step 1
1 of 3
a. The height is zero when the ball is on the ground:

$$
0=-16t^2+80t
$$

Factorize:

$$
0=-16t(t-5)
$$

Zero product property:

$$
t=0text{ or }t-5=0
$$

Solve each equation to $t$:

$$
t=0text{ or }t=5
$$

Since at $t=0s$ we hit the ball, the ball lands on the ground at $t=5s$.

Step 2
2 of 3
b. The maximum height will be attained exactly in the middle of the two roots and thus at $t=2.5$:

$$
h=-16(2.5)^2+80(2.5)=100
$$

Thus the maximum height is 100ft.

c. The domain only makes sense on $[0,5]$, because outside of this domain the function will be negative and thus this would mean that the ball is under the ground, which is impossible.

Result
3 of 3
a. 5 s

b. 100 ft

c. $[0,5]$

Exercise 86
Step 1
1 of 2
Subtract the two equations:

$$
0=x^2-6x+9
$$

Factorize:

$$
0=(x-3)^2
$$

Zero product property:

$$
0=x-3
$$

Add 3 to both sides of the equation:

$$
3=x
$$

Determine $y$:

$$
y=4x-7=4(3)-7=12-7=5
$$

Thus the graphs intersect once at $(3,5)$.

Exercise scan

Result
2 of 2
Once at $(3,5)$
Exercise 87
Step 1
1 of 3
a. The square function opens upwards:

$$
-sqrt{12}<b-4<sqrt{12}
$$

Add 4 to all sides of the inequality:

$$
4-sqrt{12}<b<4+sqrt{12}
$$

Evaluate:

$$
0.5359<b<7.4641
$$

Exercise scan

b. The square function opens upwards:

$$
x+3sqrt{4}
$$

Subtract 3 from all sides of the inequality:

$$
x-3+sqrt{4}
$$

Evaluate square root:

$$
x-3+2
$$

Evaluate sum/difference:

$$
x-1
$$

Exercise scan

Step 2
2 of 3
c.
$$
2(x-3)>4
$$
Divide both sides of the inequality by 2:

$$
x-3>2
$$

Add 3 to both sides of the inequality:

$$
x>5
$$

Exercise scan

Result
3 of 3
a. $-8<b<8$

b. $x1$

c. $x>5$

Exercise 88
Step 1
1 of 3
a. Add and subtract 4 from the given equation:

$$
f(x)=(x^2+4x+4)+5-4
$$

Factorize the perfect square trinomial ($a^2pm 2ab+b^2=(apm b)^2$):

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

Thus the vertex is then $(-2,1)$.

b. Add and subtract 12.25 from the given equation:

$$
f(x)=(x^2-7x+12.25)-12.25
$$

Factorize the perfect square trinomial ($a^2pm 2ab+b^2=(apm b)^2$):

$$
f(x)=(x-3.5)^2-12.25
$$

Thus the vertex is then $(3.5,-12.25)$.

Step 2
2 of 3
c. Since $a=1$ for both functions, both vertices represent a minimum (since both graphs then open upwards).
Result
3 of 3
a. $(-2,1)$

b. $(3.5,-12.25)$

c. Minima

Exercise 89
Step 1
1 of 3
a. Determine the area of the regular pentagon.

A pentagon has 5 vertices. Divide the pentagon into 5 congruent triangles. Determine the the height of these triangles using the tangent ratio:

$$
h=460.5tan{54text{textdegree}}approx 633.8
$$

The area of a triangles is the product of the base and the height divided by 2:

$$
dfrac{921cdot 633.8}{2}approx 291,864.9
$$

Since the pentagon is made up out of 5 triangles, the area of the pentagon is:

$$
5cdot 291,864.9=1,459,324.5 ft^2
$$

Step 2
2 of 3
b. The area in square miles is then:

$$
dfrac{1,459,324.5 }{5280^2}approx 0.0524 mi^2
$$

$$
text{color{white} jmlirjtet mjretm lijretm lrejtj erjtl jrljtlr jlktjrl jtrlj ljr litelrj tlretm ermthmre hmtlrel thmrleht hlirht lhr}
$$

Result
3 of 3
a. 1,459,324.5 ft$^2$

b. 0.0524 mi$^2$

Exercise 90
Step 1
1 of 3
Determine the missing side lengths using the Pythagorean theorem:Exercise scan
Step 2
2 of 3
The area of a trapezium is the sum of the bases, multiplied by the height divided by 2:

$$
dfrac{(15+22)4}{2}=74in^2
$$

The perimeter is the sum of all side lengths:

$$
4sqrt{2}’+15’+5’+22’=(4sqrt{2}+42)’
$$

Result
3 of 3
Area 74 in$^2$

Perimeter $(4sqrt{2}+42)’$

Exercise 91
Step 1
1 of 2
a. Use the Pythagorean theorem:

$$
r^2=x^2+y^2
$$

b. The sine ratio is the opposite side divided by the hypotenuse:

$$
sin{theta}=dfrac{y}{r}
$$

If $r=1$, we then obtain:

$$
sin{theta}=dfrac{y}{1}=y
$$

c. The cosine ratio is the adjacent rectangular side divided by the hypotenuse:

$$
cos{theta}=dfrac{x}{r}
$$

If $r=1$, we then obtain:

$$
cos{theta}=dfrac{x}{1}=x
$$

Result
2 of 2
a. $r^2=x^2+y^2$

b. $sin{theta}=dfrac{y}{r}$, $y$

c. $cos{theta}=dfrac{x}{r}$, $x$

Exercise 92
Step 1
1 of 3
a. $d$ is largest and $f$ is smallest

b. $e$ is largest and $c$ is smallest

c. $f$ is largest and $d$ is smallest

Exercise scan

Step 2
2 of 3
d. You note that for $x=100$, that the value for $f$ is already so large that we needed a … at the end of the number thus we note that $f$ will be the winner of the race to infinity.

e. The value $x$ at which the order of finish no longer changes is the largest $x$-value of all the intersections between the functions. At this point in the race the order will no longer change.

Result
3 of 3
a. $d$ is largest and $f$ is smallest

b. $e$ is largest and $c$ is smallest

c. $f$ is largest and $d$ is smallest

d. $f$

e. Largest $x$-value of all the intersections between the functions.

Exercise 93
Step 1
1 of 2
The exponential function will always win the race to infinity over the linear and quadratic functions, while the linear functions will always come in last.

If you have more than one type of the function, then the largest coefficient of $x$ (for linear), the largest coefficient of $x^2$ (for quadratic) and the largest base (for exponential) will win over the other functions of the same kind.

Result
2 of 2
The exponential function will always win the race to infinity over the linear and quadratic functions, while the linear functions will always come in last.
Exercise 94
Step 1
1 of 3
a.Exercise scan
Step 2
2 of 3
b. $f$ is always increasing, $g$ is decreasing on $(-infty,0)$ and increasing on $(0,+infty)$, and $h$ is always increasing.

c. The average rate of change is the difference in $y$-values divided by the difference in $x$-values. Let us first determine it for the interval $1leq xleq 2$:

$$
f:dfrac{3-1}{2-1}=2
$$

$$
g:dfrac{7-1}{2-1}=4
$$

$$
h:dfrac{3-1}{2-1}=2
$$

Next for the interval $2leq xleq 3$:

$$
f:dfrac{5-3}{3-2}=2
$$

$$
g:dfrac{17-7}{3-2}=10
$$

$$
h:dfrac{7-3}{3-2}=4
$$

d. We note that $f$ will keep increasing at a constant factor and thus this function will be last. The average rate of change of the other two functions are not really representative, because $h$ will increase faster than $g$, but this is not noticable yet at low $x$-values.

Result
3 of 3
a. Graph

b. $f$ and $h$ are always increasing, $g$ is decreasing on $(-infty, 0)$ while increasing on $(0,+infty)$

c.

$1leq xleq 2$: 2, 4, 2

$2leq xleq 3$: 2, 10, 4

d. $h$ first and $f$ last

Exercise 95
Step 1
1 of 3
a.Exercise scan
Step 2
2 of 3
b. The average rate of change is the difference in $y$-values divided by the difference in $x$-values:

$$
Mateo: dfrac{1400-1000}{2-0}=200
$$

$$
Marcy: dfrac{1251.4-1085}{2-0}=83.2
$$

c. The average rate of change is the difference in $y$-values divided by the difference in $x$-values:

$$
Mateo: dfrac{2000-1600}{5-3}=200
$$

$$
Marcy: dfrac{1554.33-1344.71}{5-3}=108.81
$$

d. Marcy’s account will have more money in the long run because the average rate of change will keep increasing, while Mateo’s rate of change will remain constant.

Result
3 of 3
a. Table

b. 200, 83.2

c. 200, 108.81

d. Marcy’s account

Exercise 96
Step 1
1 of 2
Subtract the two equations:

$$
0=x^2+0.6x-0.55
$$

Factorize:

$$
0=0.05(2x-1)(10x+11)
$$

Zero product property:

$$
2x-1=0text{ or }10x+11=0
$$

Solve each equation to $x$:

$$
2x=1text{ or }10x=-11
$$

$$
x=dfrac{1}{2}text{ or }x=-dfrac{11}{10}
$$

Exercise scan

Result
2 of 2
$$
x=dfrac{1}{2}text{ and }x=-dfrac{11}{10}
$$
Exercise 97
Step 1
1 of 2
a. The height of the platform is the height at $t=0$:

$$
h=11
$$

Thus the height of the platform is 11 meters.

b. The firwork hits the ground at $h=0$:

$$
0=-4.9t^2+50t+11
$$

Determine the roots using the quadratic formula:

$$
t=dfrac{-50pmsqrt{50^2-4(-4.9)(11)}}{2(-4.9)}=dfrac{-50pm sqrt{2715.6}}{-9.8}approx -0.2text{ or }10.4
$$

Thus the firework hits the ground after about 10.4 seconds.

c. The maximum height is attained at the line of symmetry:

$$
t=-dfrac{50}{2(-4.9)}approx 5.1
$$

The corresponding height is then the maximum height:

$$
h=-4.9(5.1)^2+50(5.1)+11approx 139
$$

Thus the maximum height is about 11 meters.

Result
2 of 2
a. 11 meters

b. 10.4 seconds

c. 11 meters

Exercise 98
Step 1
1 of 2
a. The graph of $y=f(x)$ is translated up by 3 units.

b. The graph of $y=f(x)$ is stretched vertically by factor 3.

c. The graph of $y=f(x)$ is translated left by 3 units.

Exercise scan

Result
2 of 2
a. Translated 3 units up

b. Stretch vertically by factor 3

c. Translate to the left by 3 units

Exercise 99
Step 1
1 of 2
a. The sum of all angles in a pentagon is 540$text{textdegree}$:

$$
2x+4x-3+7x-6+3x+12+x+10=540
$$

Combine like terms:

$$
17x+13=540
$$

Subtract 13 from both sides of the equation:

$$
17x=527
$$

Divide both sides of the equation by 17:

$$
x=31
$$

b. Vertical angles are congruent and same-side interior angles of parallel lines are supplementary:

$$
4x+20+5x-2=180
$$

Combine like terms:

$$
9x+18=180
$$

Subtract 18 from both sides of the equation:

$$
9x=162
$$

Divide both sides of the equation by 9:

$$
x=18
$$

Result
2 of 2
a. $x=31$

b. $x=18$

Exercise 100
Step 1
1 of 2
a. Multiply both sides of the equation by 360:

$$
360A=theta pi r^2
$$

Divide both sides of the equation by $pi r^2$:

$$
dfrac{360A}{pi r^2}=theta
$$

Interchange the left and right side of the equation:

$$
theta=dfrac{360A}{pi r^2}
$$

b. Multiply both sides of the equation by 360:

$$
360A=theta pi r^2
$$

Divide both sides of the equation by $theta pi$:

$$
dfrac{360A}{theta pi}=r^2
$$

Take the square root of both sides of the equation:

$$
sqrt{dfrac{360A}{theta pi}}=r
$$

Interchange the left and right side of the equation:

$$
r=sqrt{dfrac{360A}{theta pi}}
$$

Result
2 of 2
a. $theta=frac{360A}{pi r^2}$

b. $r=sqrt{frac{360A}{thetapi}}$

Exercise 101
Step 1
1 of 2
a. The ratio of the areas is the linear scale factor squared:

$$
left( dfrac{2}{5}right)^2=dfrac{4}{25}
$$

b. The ratio of the areas is the ratio of the perimeters squares:

$$
14^2:1^2=196:1
$$

c. The ratio of the perimeters is the square root of the ratio of the areas:

$$
sqrt{81}=9
$$

Result
2 of 2
a. $frac{4}{25}$

b. 196:1

c. 9

Exercise 102
Step 1
1 of 2
a. The monthly fee includes 450 minutes and the charge for each additional minute is $0.50.

b. The domain contains only nonnegative integer values (since the time cannot be negative):

$$
f(t)=450
$$

c. The second piece is $f(t)=450.50$ while the third piece is $f(t)=451$.

d. Yes, because for every $x$-value, there is exactly one corresponding $y$-value.

e. Because the graph takes on the shape of steps (of a staircase). Other situations are for example the greatest integer of real numbers.

Result
2 of 2
a. 450 minutes, $$0.50$

b. $f(t)=450$

c. $f(t)=450.50$, $f(t)=451$

d. Yes

c. Shape of steps of a staircase, greatest integer of real numbers.

Exercise 103
Step 1
1 of 3
a.Exercise scan
Step 2
2 of 3
b.Exercise scan
Result
3 of 3
See graphs
Exercise 104
Step 1
1 of 3
a.Exercise scan
Step 2
2 of 3
b. Continuous, because she can’t leave a place and appear in another place at an instant, she actually has to walk or run there.

c.
$$
f(x)=left{ begin{matrix} dfrac{1}{10}x & 0leq x leq 10 \ 1 & 10<xleq 20\ -dfrac{1}{12}(x-32) & 20<xleq 32end{matrix}right.
$$

Result
3 of 3
Continuous,
$$
f(x)=left{ begin{matrix} dfrac{1}{10}x & 0leq x leq 10 \ 1 & 10<xleq 20\ -dfrac{1}{12}(x-32) & 20<xleq 32end{matrix}right.
$$
Exercise 105
Step 1
1 of 2
a. He has to pay the basic fee increase by the product of the billin rate and the HCF:
$$
$37.78+10cdot $3.64=$74.18
$$

b. He has to pay the basic fee increase by the product of the billin rate and the HCF:
$$
$37.78+dfrac{30,000}{748.05}cdot $8.19=$366.23
$$

c.
$$
dfrac{$200-$37.78}{$5.82}=27.87HCF=20,850gallons
$$

Thus the water usage needs to be reduced by about 10,000 gallons for the bill to be than $200.

$$
dfrac{$150-$37.78}{$4.08}=27.5HCF>24HCF=17,953gallons
$$

Thus the water usage needs to be reduced by about 12,000 gallons for the bill to be than $150.

\
\

d.$
$$
f(x)=left{ begin{matrix}3.64x & 0leq xleq 8 \ 4.08x & 8<xleq 24 \ 5.82x & 24<xleq 36\ 8.19x & 36<xend{matrix}right.
$$
$

Result
2 of 2
a. $$74.18$

b. $$366.23$

c. 10,000 gallons, 12,000 gallons

d.
$$
f(x)=left{ begin{matrix}3.64x & 0leq xleq 8 \ 4.08x & 8<xleq 24 \ 5.82x & 24<xleq 36\ 8.19x & 36<xend{matrix}right.
$$

Exercise 106
Step 1
1 of 2
Piecewise-Defined functions

Piecewise-Defined functions contain multiply expression for the function definition, where each expression is defined on a different interval.

Result
2 of 2
Piecewise-Defined functions contain multiply expression for the function definition, where each expression is defined on a different interval.
Exercise 107
Step 1
1 of 3
a.Exercise scan
Step 2
2 of 3
b.
$$
f(x)=left{ begin{matrix}x & xgeq 0 \ -x & x<0end{matrix}right.
$$
Result
3 of 3
$$
f(x)=left{ begin{matrix}x & xgeq 0 \ -x & x<0end{matrix}right.
$$
Exercise 108
Step 1
1 of 2
Let the given expression equal 6:

$$
(x-1)^2+2=6
$$

Subtract 2 from both sides of the equation:

$$
(x-1)^2=4
$$

Take the square root of both sides of the equation:

$$
x-1=pm 2
$$

Add 1 to both sides of the equation:

$$
x=1pm 2=3text{ or }-1
$$

Thus 3 or $-1$ has been dropped in.

Result
2 of 2
3 or $-1$
Exercise 109
Step 1
1 of 2
If the function equation is of the form $f(x)=a(x-h)^2+k$, then the vertex is $(h,k)$.

a. The vertex is $(-1,-5)$ and since $a=2$ is positive, the function opens upwards and thus the vertex is a minimum.

b. The value of the function at the minimum is the $y$-coordinate of the vertex (see part (a)) and thus is $y=-5$.

Result
2 of 2
a. $(-1, -5)$, minimum

b. $y=-5$

Exercise 110
Step 1
1 of 2
Determine the area of the regular pentagon.

A pentagon has 5 vertices. Divide the pentagon into 5 congruent triangles. Determine the the height these triangles using the tangent ratio:

$$
h=5tan{54text{textdegree}}approx 6.8819
$$

The area of a triangles is the product of the base and the height divided by 2:

$$
dfrac{10cdot 6.8819}{2}=34.4095
$$

Since the shaded region of the pentagon is made up out of 3 triangles, the area of the shaded region is:

$$
3cdot 34.4095=103.2285units^2approx 103 units^2
$$

Result
2 of 2
$$
103 units^2
$$
Exercise 111
Step 1
1 of 2
The probability of landing on green once is the root of the probability of landing on green twice:

$$
P(green)=sqrt{16%}=sqrt{0.16}=0.4=40%
$$

The probability of purple is then the complement:

$$
P(purple)=1-0.4=0.6=60%
$$

The probability of landing on purple twice is then the product of each probability:

$$
P(PurpleTwice)=0.6cdot 0.6=0.36=36%
$$

Result
2 of 2
36%
Exercise 112
Step 1
1 of 2
a. The ratio of the heights:

$$
dfrac{11}{33}=dfrac{1}{3}
$$

b. The ratio of the areas is the linear scale factor squared:

$$
left( dfrac{1}{3}right)^2=dfrac{1}{9}
$$

Result
2 of 2
a. $frac{1}{3}$

b. $frac{1}{9}$

Exercise 113
Step 1
1 of 2
a. Determine the value of each function at $x=10$:

$$
g(10)=10(10)^2=1000
$$

$$
h(10)=1.01^{10}=1.104622125
$$

$$
m(10)=0.01(2)^{10}=10.24
$$

Thus we note that $g$ is ahead.

b. The average rate of change is the difference in $y$-values divided by the difference in $x$-values:

$$
g: dfrac{40-0}{2-0}=20
$$

$$
h: dfrac{1.0201-1}{2-0}=0.01005
$$

$$
m: dfrac{0.04-0.01}{2-0}=0.015
$$

c. From the table we note that the equation of $m$ is
$$
m(x)=0.01cdot 2^x
$$

d. The function $m$ will win, because it is the exponential function with the largest base. Then determine when it will take the lead:

$$
1.01^x=0.01(2)^x
$$

Divide both sides of the equation by $1.01^x$:

$$
1=0.01left( dfrac{2}{1.01}right)^x
$$

Multiply both sides of the equation by 100:

$$
100=left( dfrac{2}{1.01}right)^x
$$

Then we note that if $x=7$ the function $m$ will take the lead.

Result
2 of 2
a. $g$

b.20, 0.01005, 0.015

c. $m(x)=0.01cdot 2^x$

d. $m$, $x=7$

Exercise 114
Step 1
1 of 2
Replace the functions with their expressions:

a. The function $a$ is quadratic:

$$
a(x)=f(x)+c(x)=x^2+3
$$

b. The function $b$ is quadratic:

$$
b(x)=c(x)cdot g(x)=3x^2
$$

c. The function $d$ is linear:

$$
d(x)=g(x)-c(x)=2x+1-3=2x-2
$$

d. The function $e$ is linear:

$$
e(x)=c(x)cdot g(x)=3cdot (2x+1)=6x+3
$$

Result
2 of 2
a. $a(x)=x^2+3$

b. $b(x)=3x^2$

c. $d(x)=2x-2$

d. $e(x)=6x+3$

Exercise 115
Step 1
1 of 3
a.Exercise scan
b.Exercise scan
Step 2
2 of 3
c.Exercise scan
d. If you multiply a quadratic function by a linear function, you will obtain a third-degree function, the graph will then be a curve.

e. NoExercise scan

Result
3 of 3
a. Graph

b. Table

c. parabolas

c. Cubic Curve

e. No

Exercise 116
Step 1
1 of 4
If the vertex is $(h,k)$ then the function equation is of the form $f(x)=a(x-h)^2+k$.

a. Replace $h$ with 22 and $k$ with 43:

$$
h(x)=a(x-22)^2+43
$$

Replace $x$ with 100 and $h(x)$ with 0:

$$
0=a(100-22)^2+43=6084a+43
$$

Subtract 43 from both sides of the equation:

$$
-43=6084a
$$

Divide both sides of the equation by 6084:

$$
-dfrac{43}{6084}=a
$$

Replace $a$ with its value:
$$
h(x)=-dfrac{43}{6084}(x-22)^2+43
$$

Step 2
2 of 4
b. Replace $h$ with 24 and $k$ with 45:

$$
j(x)=a(x-24)^2+45
$$

Replace $x$ with 0 and $j(x)$ with 40:

$$
40=a(0-24)^2+45=576a+45
$$

Subtract 45from both sides of the equation:

$$
-5=576
$$

Divide both sides of the equation by 2025:

$$
-dfrac{5}{576}=a
$$

Replace $a$ with its value:
$$
j(x)=-dfrac{5}{576}(x-24)^2+45
$$

Step 3
3 of 4
c. Evaluate $h$ at $x=24$:

$$
h(24)=-dfrac{43}{6084}(24-22)^2+43approx 42.97
$$

Determine the difference in heights:

$$
45-42.97=2.03
$$

Thus the skier is about 2.03 ft about the landing hill at her peak.

Result
4 of 4
a. $h(x)=-frac{43}{6084}(x-22)^2+43$

b. $j(x)=-frac{5}{576}(x-24)^2+45$

c. 2.03 ft

Exercise 117
Step 1
1 of 3
a. You could use the difference function:
$$
f(x)=j(x)-h(x)
$$

b. We note on the graph that the skier lands at about $x=70$ ft.

Exercise scan

Step 2
2 of 3
c.
$$
f(x)=left{ begin{matrix} j(x) & 0leq x leq 70\ h(x) & x>70end{matrix}right.
$$
Result
3 of 3
a. $f(x)=j(x)-h(x)$

b. $x=70$ ft

c.
$$
f(x)=left{ begin{matrix} j(x) & 0leq x leq 70\ h(x) & x>70end{matrix}right.
$$

Exercise 118
Step 1
1 of 3
a. Replace $x$ with 0:

$$
y=f(0)=0^2+0-6=-6
$$

b. Replace $f(x)$ with 0:

$$
0=x^2+x-6
$$

Factorize:

$$
0=(x+3)(x-2)
$$

Zero product property:

$$
x+3=0text{ or }x-2=0
$$

Solve each equation to $x$:

$$
x=-3text{ or }x=2
$$

Thus the $x$-intercepts are $x=-3$ and $x=2$.

Step 2
2 of 3
c. Replace the functions with their expressions:

$$
g(x)=f(x)+c(x)=x^2+x-6+6=x^2+x
$$

d. Since the function $g$ is the function $f$ translated up by 6 units, we know that the $y$-intercept is $y=0$ and the $x$-intercepts is $x=0$ and $x=-1$:

Exercise scan

Result
3 of 3
a. $(0,-6)$

b. $(-3,0)$ and $(2,0)$

c. $g(x)=x^2+x$

d.

$x$-intercepts: $(0,0)$ and $(1,0)$

$y$-intercepts: $(0,0)$

Exercise 119
Step 1
1 of 2
A line has equation $y=ax+b$ with $a$ the slope and $b$ the $y$-intercept.

The left part of the function has $y$-intercept $b=-3$ and the slope is
$$
a=dfrac{y_2-y_1}{x_2-x_1}=dfrac{1+3}{2-0}=2
$$

Thus the equation of the left part of the equation is then $y=2x-3$.

The right part of the function has $y$-intercept $b=1$ (if you draw the line further) and the slope is
$$
a=dfrac{y_2-y_1}{x_2-x_1}=dfrac{5-3}{4-2}=1
$$

Thus the equation of the left part of the equation is then $y=1x+1=x+1$.

Then the equation of the piecewise function:

$$
f(x)=left{ begin{matrix} 2x-3 & x<2\ x+1 & xgeq 2end{matrix} right.
$$

Result
2 of 2
$$
f(x)=left{ begin{matrix} 2x-3 & x<2\ x+1 & xgeq 2end{matrix} right.
$$
Exercise 120
Step 1
1 of 2
The expected value is the sum of the product of the possibility and the probability of the possibility:

$$
EV=$3cdot dfrac{3}{12}-$1 cdot dfrac{7}{12}+$ 10cdot dfrac{2}{12}approx $1.83
$$

The game is not fair, because the expected value is not zero. Since the expected value is positive, the person that selects the beads will have the advantage in this game.

Result
2 of 2
Not fair
Exercise 121
Step 1
1 of 3
a. The rocket reaches the ground if $h=0$:

$$
0=-16t^2+92t
$$

Factorize:

$$
0=-4t(4t-23)
$$

Zero product property:

$$
t=0text{ or }4t-23=0
$$

Solve each equation to $t$:

$$
t=0text{ or }4t=23
$$

$$
t=0text{ or }t=dfrac{23}{4}=5.75
$$

Thus at 5.75 seconds the rocket reaches the ground (again).

b.
$$
-16t^2+92t>76
$$

Subtract 76 from both sides of the inequality:

$$
-16t^2+92t-76>0
$$

Factorize

$$
-4(t-1)(4t-19)>0
$$

Since the function $y=-4(t-1)(4t-19)$ opens downwards:

$$
1leq t leq 4.75
$$

Step 2
2 of 3
c. No, because the rocket is off the ground for 3.75 seconds (difference between the boundaries found in (b)).
d. An oppropriate domain contains all times for which the rocket is above or on the ground:

$$
Domain=[0,5.75]
$$

Result
3 of 3
a. 5.75 seconds

b. $-16t^2+92t>76$, $1leq tleq 4.75$

c. No

d. $[0,5.75]$

Exercise 122
Step 1
1 of 3
a. If $x=a$ is an $x$-intercept, then the function equation contains a factor $(x-a)$ Thus the function of this graph is then of the form:

$$
y=a(x+9)(x-5)
$$

If $x=0$, then $y=11.25$:

$$
11.25=a(9)(-5)=-45a
$$

Divide both sides of the equation by $-45$:

$$
-0.25=a
$$

Replace $a$ with its value:

$$
y=-0.25(x+9)(x-5)
$$

b. If $x=a$ is an $x$-intercept, then the function equation contains a factor $(x-a)$ Thus the function of this graph is then of the form:

$$
y=a(x+7)(x+4)
$$

If $x=-5.5$, then $y=-4.5$:

$$
-4.5=a(1.5)(-1.5)=-2.25a
$$

Divide both sides of the equation by $-2.25$:

$$
2=a
$$

Replace $a$ with its value:

$$
y=2(x+7)(x+4)
$$

Step 2
2 of 3
c. If $x=a$ is an $x$-intercept, then the function equation contains a factor $(x-a)$ Thus the function of this graph is then of the form:

$$
y=a(x+6)^2
$$

If $x=0$, then $y=12$:

$$
12=a(6)^2=36a
$$

Divide both sides of the equation by $36$:

$$
dfrac{1}{3}=a
$$

Replace $a$ with its value:

$$
y=dfrac{1}{3}(x+6)^2
$$

Result
3 of 3
a. $y=-0.25(x+9)(x-5)$

b. $y=2(x+7)(x+4)$

c. $y=frac{1}{3}(x+6)^2$

Exercise 123
Step 1
1 of 2
The circumference of a circle is $C=2pi r$, thus the circumference of the car tires is:

$$
C=2pi 14=28pi in.
$$

Then the distance is the product of the time, the numner of revolutions per time and the circumference of the tire:

$$
5cdot 120cdot 28pi in.=16,800 pi in.
$$

Result
2 of 2
D
Exercise 124
Step 1
1 of 2
a. The perimeter of $triangle ABE$ is the sum of all sides:

$$
P_s=7+3+5=15
$$

Since $triangle ABC$ and $triangle ACD$ are similar with scale factor 2, the perimeter is then also multiplied by the scale factor 2:

$$
P_l=2cdot 15=30units
$$

b. The area of the larger triangle is the product of the area of the smaller triangle with the scale factor squared:

$$
A_l=2^2cdot 6.5=26 units^2
$$

Result
2 of 2
a. 30 units

b. 26 units$^2$

Exercise 125
Step 1
1 of 2
a. The function multiplies the input by 3 and then increases it by 4.

$$
f(x)=3x+4
$$

b. If 16 is put in, then 4 should come out and if $-5$ is put in, then $-3$ should come out.

c. The function would first need to subtract 4 and then divided the number by 3.

d. Thus the function equation then becomes:

$$
f^{-1}(x)=dfrac{1}{3}(x-4)
$$

Result
2 of 2
a. $f(x)=3x+4$

b. $-3$

c. Subtract 4, Divide by 3

d. $f^{-1}(x)=frac{1}{3}(x-4)$

Exercise 126
Step 1
1 of 2
a. First multiply $x$ by 5:

$$
5x
$$

Then subtract 8:

$$
5x-8
$$

Finally divide by 2:

$$
dfrac{1}{2}(5x-8)
$$

Thus the equation is then:

$$
g(x)=dfrac{1}{2}(5x-8)
$$

Let $x$ be 3:

$$
g(3)=dfrac{1}{2}(5(3)-8)=dfrac{7}{2}=3.5
$$

b. First multiply $x$ by 2:

$$
2x
$$

Then add 8 8:

$$
2x+8
$$

Finally divide by 5:

$$
dfrac{1}{5}(2x+8)
$$

Thus the equation is then:

$$
g^{-1}(x)=dfrac{1}{5}(2x+8)
$$

Result
2 of 2
a. $g(x)=frac{1}{2}(5x-8)$, 3.5

b. $g^{-1}(x)=frac{1}{5}(2x+8)$

Exercise 127
Step 1
1 of 2
a. Replace $n(x)$ with $y$:

$$
y=4x-12
$$

Interchange $x$ and $y$:

$$
x=4y-12
$$

Solve the equation to $y$ by first adding 12 to both sides of the equation:

$$
x+12=4y
$$

Divide both sides of the equation by 4:

$$
dfrac{1}{4}(x+12)=y
$$

Interchange left and right side of the equation and replace $y$ with $n^{-1}(x)$:

$$
n^{-1}(x)=dfrac{1}{4}(x+12)
$$

b. Replace $j(x)$ with $y$:

$$
y=dfrac{x-7}{10}
$$

Interchange $x$ and $y$:

$$
x=dfrac{y-7}{10}
$$

Solve the equation to $y$ by first multiplying both sides of the equation by 10:

$$
10x=y-7
$$

Add 7 to both sides of the equation:

$$
10x+7=y
$$

Interchange left and right side of the equation and replace $y$ with $j^{-1}(x)$:

$$
j^{-1}(x)=10x+7
$$

Result
2 of 2
a. $n^{-1}(x)=frac{1}{4}(x+12)$

b. $j^{-1}(x)=10x+7$

Exercise 128
Step 1
1 of 3
a. When $C=0$ we need that $F=32$:

$$
F=aC+32
$$

When $C=100$, then $F=212$:

$$
212=100a+32
$$

Subtract 32 from both sides of the equation:

$$
180=100a
$$

Divide both sides of the equation by 100:

$$
dfrac{9}{5}=a
$$

Replace $a$ with its value:

$$
F=dfrac{9}{5}C+32
$$

b. Evaluate at $C=30$ and $C=25$:

$$
F=dfrac{9}{5}(30)+32=86
$$

$$
F=dfrac{9}{5}(25)+32=77
$$

Thus it will be 86$text{textdegree}$ F warm and 77$text{textdegree}$ F cold.

Step 2
2 of 3
c. We know that 32 needs to be a root of the function:

$$
C=a(x-32)
$$

When $F=212$, then $C=100$:

$$
100=a(212-32)=180a
$$

Divide both sides of the equation by 180:

$$
dfrac{5}{9}=a
$$

Replace $a$ with its value:

$$
y=dfrac{5}{9}(x-32)
$$

d. The functions are each others inverse.
Result
3 of 3
a. $F=frac{9}{5}C+32$

b. 86$text{textdegree}$ F warm and 77$text{textdegree}$ F cold

c. $y=frac{5}{9}(x-32)$

d. Inverses

Exercise 129
Step 1
1 of 3
a. Replace $h(x)$ with $y$:

$$
y=2x-1
$$

Interchange $x$ and $y$:

$$
x=2y-1
$$

Solve the equation to $y$ by first adding 1 to both sides of the equation:

$$
x+1=2y
$$

Divide both sides of the equation by 2:

$$
dfrac{1}{2}(x+1)=y
$$

Interchange left and right side of the equation and replace $y$ with $h^{-1}(x)$:

$$
h^{-1}(x)=dfrac{1}{2}(x+1)
$$

b. The $x$-intercept of $h$ is the $y$-intercept of $h^{-1}$ (coordinates were interchanged) and the $y$-intercept of $h$ is the $x$-intercept of $h^{-1}$ (coordinates were interchanged).

Exercise scan

Step 2
2 of 3
c. The values of the two columns have been interchanged:Exercise scan
Result
3 of 3
a. $h^{-1}(x)=frac{1}{2}(x+1)$

b. Intercepts interchange

c. Values two columns interchange.

Exercise 130
Step 1
1 of 3
a.Exercise scan
b. Interchange the two columns.Exercise scan
Step 2
2 of 3
c. No, because for example $x=1$ has image $y=-1$ and $y=1$.

Exercise scan

d. There are two possible inverses. If $x$ of the original function is nonnegative:

$$
f^{-1}(x)=sqrt{x}
$$

If $x$ of the original function is nonpositive:

$$
f^{-1}(x)=-sqrt{x}
$$

Result
3 of 3
a. Table

b. Swith columns of table of part (a)

c. No

d. $f^{-1}(x)=pm sqrt{x}$

Exercise 131
Step 1
1 of 2
a. Replace $p(x)$ with $y$:

$$
y=x^2+2
$$

Interchange $x$ and $y$:

$$
x=y^2+2
$$

Solve the equation to $y$ by first subtracting 2 from both sides of the equation:

$$
x-2=y^2
$$

Assume that $x$ is positive in the original function. Take the square root of both sides of the equation:

$$
sqrt{x-2}=y
$$

Interchange left and right side of the equation and replace $y$ with $p^{-1}(x)$:

$$
p^{-1}(x)=sqrt{x-2}
$$

b. Replace $q(x)$ with $y$:

$$
y=2(x-3)
$$

Interchange $x$ and $y$:

$$
x=2(y-3)
$$

Solve the equation to $y$ by first dividing both sides of the equation by 2:

$$
dfrac{1}{2}x=y-3
$$

Add 3 to both sides of the equation:

$$
dfrac{1}{2}x+3=y
$$

Interchange left and right side of the equation and replace $y$ with $q^{-1}(x)$:

$$
q^{-1}(x)=dfrac{1}{2}x+3
$$

Result
2 of 2
a. $p^{-1}(x)=sqrt{x-2}$

b. $q^{-1}(x)=frac{1}{2}x+3$

Exercise 132
Step 1
1 of 2
a. Replace $f(x)$ with $y$:

$$
y=2x+3
$$

Interchange $x$ and $y$:

$$
x=2y+3
$$

Solve the equation to $y$ by first subtracting 3 from both sides of the equation:

$$
x-3=2y
$$

Divide both sides of the equation by 2:

$$
dfrac{1}{2}(x-3)=y
$$

Interchange left and right side of the equation and replace $y$ with $f^{-1}(x)$:

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

b. Replace $g(x)$ with $y$:

$$
y=dfrac{x-5}{4}
$$

Interchange $x$ and $y$:

$$
x=dfrac{y-5}{4}
$$

Solve the equation to $y$ by first multiplying both sides of the equation by 4:

$$
4x=y-5
$$

Add 5 to both sides of the equation:

$$
4x+5=y
$$

Interchange left and right side of the equation and replace $y$ with $g^{-1}(x)$:

$$
g^{-1}(x)=4x+5
$$

Result
2 of 2
a. $f^{-1}(x)=frac{1}{2}(x-3)$

b. $g^{-1}(x)=4x+5$

Exercise 133
Step 1
1 of 2
a. (i) The function is an exponential function with initial value $10$ and every consecutive value is multiplied by 1.05.

(ii) The function is quadratic with a vertex at $(-2,4)$ and $y$-intercept at $y=24$.

b. The exponential growth will increase faster than the quadratic function as $x$ gets large and the exponential function will then give larger values than the quadratic function.

Exercise scan

Result
2 of 2
a. (i) Exponential (ii) Quadratic

b. Exponential grows faster than quadratic

Exercise 134
Step 1
1 of 3
a.Exercise scan
b. If $x=a$ is an $x$-intercept, then $(x-a)$ is a factor of the equation. Thus
$$
y=(x-2)(x-5)
$$

is a possible equation of the given graph.

c. We can factorize the equation:

$$
y=(x+7)(x+1)
$$

Then we know that $x=-7$ and $x=-1$ are the $x$-intercepts. The vertex lies in the middle of the two intercepts and thus at $x=-4$:

$$
y=(-4+7)(-4+1)=-9
$$

Thus the vertex is $(-4,-9)$.

Exercise scan

Step 2
2 of 3
d. Factorize:

$$
y=16x(8-x)
$$

Thus the $x$-intercepts are $x=0$ and $x=8$. The vertex then lies in the middle of the intercepts and thus at $x=4$:

$$
y=128(4)-16(4)^2=256
$$

Thus the maximal height is 256ft after 4 seconds.

Result
3 of 3
a. Graph

b. $y=(x-2)(x-5)$

c. $(-4,-9)$

d. 256 ft

Exercise 135
Step 1
1 of 2
Replace the functions with their expressions:

a.
$$
s(x)=f(x)+g(x)=x^2+2x+1+x-3=x^2+3x-2
$$

b.
$$
m(x)=f(x)-g(x)=x^2+2x+1-(x-3)=x^2+x+4
$$

c.
$$
v(x)=2f(x)=2(x^2+2x+1)=2x^2+4x+2
$$

d.
$$
d(x)=g(x)-f(x)=x-3-(x^2+2x+1)=-x^2-x-4
$$

Result
2 of 2
a. $x^2+3x-2$

b. $x^2+x+4$

c. $2x^2+4x+2$

d. $-x^2-x-4$

Exercise 136
Step 1
1 of 2
The length of the unknown part is the length of the total segment decreased by the length of the known part:

a. $x-2$

b. $5-x$

Result
2 of 2
a. $x-2$

b. $5-x$

Exercise 137
Step 1
1 of 2
The area of the square is the length of its side squared:

$$
A_s=6^2=36
$$

The area of the circle is the product of $pi$ and the radius squared (note: The radius is half the width of the square):

$$
A_c=pi 3^2=9pi
$$

The area of the part of the square outside the circle is then:

$$
A=A_s-A_c=36-9pi
$$

Only half of this area is shaded:

$$
dfrac{36-9pi}{2}=18-dfrac{9}{2}pi units^2approx 3.8628units^2
$$

Result
2 of 2
$18-dfrac{9}{2}pi units^2$ or approximately $3.8628units^2$
Exercise 138
Step 1
1 of 2
The area of a trapezium is the sum of the bases, multiplied by the height and divided by 2. The area of a triangle is the product of the base and the height divided by 2. The area of a rectangle is the product of the length and the base:

$$
A=dfrac{(13+9)3}{2}+dfrac{4cdot 8}{2}+9cdot 5=33+16+45=94
$$

The perimeter is the sum of all lengths of the sides:

$$
P=17+5+5+9+4sqrt{5}=36+4sqrt{5}
$$

Exercise scan

Result
2 of 2
Area 94

Perimater $36+4sqrt{5}$

Exercise 139
Step 1
1 of 3
a. Replace $f(x)$ with $y$:

$$
y=2x-3
$$

Interchange $x$ and $y$:

$$
x=2y-3
$$

Solve the equation to $y$ by first adding 3 to both sides of the equation:

$$
x+3=2y
$$

Divide both sides of the equation by 2:

$$
dfrac{1}{2}(x+3)=y
$$

Interchange left and right side of the equation and replace $y$ with $f^{-1}(x)$:

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

b. Assuming that $xgeq 0$. Replace $h(x)$ with $y$:

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

Interchange $x$ and $y$:

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

Solve the equation to $y$ by first subtract 2 from both sides of the equation:

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

Take the square root of both sides of the equation:

$$
sqrt{x-2}=y-3
$$

Add 3 to both sides of the equation:

$$
sqrt{x-2}+3=y
$$

Interchange left and right side of the equation and replace $y$ with $h^{-1}(x)$:

$$
h^{-1}(x)=sqrt{x-2}+3
$$

Step 2
2 of 3
c. In (b) we asssumed that $xgeq 0$ for $h$ and thus the domain of $h$ is assumed to be $[0,+infty)$.
Result
3 of 3
a. $f^{-1}(x)=frac{1}{2}(x+3)$

b. $h^{-1}(x)=sqrt{x-2}+3$

c. $[0,+infty)$

Exercise 140
Step 1
1 of 2
a. Subtract the two equations:

$$
0=2x^2-8x+6
$$

Factorize:

$$
0=2(x-3)(x-1)
$$

Zero product property:

$$
x-3=0text{ or }x-1=0
$$

Solve each equation to $x$:

$$
x=3text{ or }x=1
$$

Determine $y$:

$$
y=x^2-4x+5=3^2-4(3)+5=2
$$

$$
y=x^2-4x+5=1^2-4(1)+5=2
$$

Thus the solutions are: $(3,2)$ and $(1,2)$.

b. Subtract the two equations:

$$
0=-3x-3
$$

Add 3 to both sides of the equation:

$$
3=-3x
$$

Divide both sides of the equation by 3:

$$
-1=x
$$

Determine $y$:

$$
y=x^2-x-2=(-1)^2-(-1)-2=0
$$

Thus the solutions is: $(-1,0)$.

Result
2 of 2
a. $(3,2)$ and $(1,2)$

b. $(-1,0)$

Exercise 141
Step 1
1 of 2
a. The ORANGE graph is the given graph translated down by 1 unit.

b. The BLUE graph is the given graph reflected about the $x$-axis.

c. The PINK graph is the graph translated to the right by 1 unit.

Exercise scan

Result
2 of 2
a. Translated down by 1 unit

b. Reflect about $x$-axis

c. Translate right by 1 unit

Exercise 142
Step 1
1 of 11
The goals for this exercise are finding out what functions represents the income of Jill and expenses of children given certain conditions.
Step 2
2 of 11
**a**.

Solving for the function $M$ which represents the income of Jill with $x$ number of children.

Step 3
3 of 11
Based on the given values, the piecewise function will be,
$$begin{aligned}
M(x)&= begin{cases}
50 &text{$xleq6$}\
50+5(x-6) &text{$x>6$}\
end{cases}
end{aligned}$$
Step 4
4 of 11
Simplifying the equation of restriction ($x>6$).
$$begin{aligned}
M(x)&= begin{cases}
50 &text{$xleq6$}\
50+5x-30 &text{$x>6$}\
end{cases}\
M(x)&= begin{cases}
50 &text{$xleq6$}\
20+5x &text{$x>6$}\
end{cases}
end{aligned}$$
Step 5
5 of 11
For $20$ children ($x>6$), Jill’s income will be,
$$begin{aligned}
M(x)&=20+5x\
M(x)&=20+5(20)\
M(x)&=120\
end{aligned}$$
Step 6
6 of 11
**b**. The function $E$ which is the expenses of Jill in the party for $x$ number of children will be,
$$begin{aligned}
E(x)&=3x
end{aligned}$$
Step 7
7 of 11
**c**. Jill’s net income which is represented by function of $N$ will be,
$$begin{aligned}
N(x)&=M(x)-E(x)\
end{aligned}$$
Step 8
8 of 11
**d**. The piecewise function of $N$ will be,
$$begin{aligned}
N(x)&= begin{cases}
M(x)-E(x) &text{$xleq6$}\
M(x)-E(x) &text{$x>6$}\
end{cases}\
end{aligned}$$
Step 9
9 of 11
Substituting the values of $M(x)$ and $E(x)$ based on restrictions.
$$begin{aligned}
N(x)&= begin{cases}
50-3x &text{$xleq6$}\
20+5x-3x &text{$x>6$}\
end{cases}\
N(x)&= begin{cases}
50-3x &text{$xleq6$}\
20+2x &text{$x>6$}\
end{cases}\
end{aligned}$$
Step 10
10 of 11
For $6$ children ($xleq6$), **Jill’s net income** will be,
$$begin{aligned}
N(x)&=50-3x\
N(x)&=50-3(6)\
N(x)&=32
end{aligned}$$
Step 11
11 of 11
For 20 children ($x>6$), **Jill’s net income** will be,
$$begin{aligned}
N(x)&=20+2x\
N(x)&=20+2(20)\
N(x)&=60
end{aligned}$$
Exercise 143
Step 1
1 of 3
Add and subtract $16$:

$$
y=(x^2+8+16)-16
$$

Factorize the perfect square trinomial ($a^2pm 2ab+b^2=(apm b)^2$):

$$
y=(x+4)^2-16
$$

Thus the vertex is then $(-4,-16)$.

Determine the $x$-intercepts using the initial equation:

$$
0=x^2+8x
$$

Factorize:

$$
0=x(x+8)
$$

Zero product property:

$$
x=0text{ or }x+8=0
$$

Solve each equation to $x$:

$$
x=0text{ or }x=-8
$$

Thus the $x$-intercepts are $x=0$ and $x=-8$.

Step 2
2 of 3
Exercise scan
Result
3 of 3
Vertex $(-4,-16)$

$x$-intercepts: $x=0$ and $x=-8$

Exercise 144
Step 1
1 of 2
a. If the exterior angle is 120$text{textdegree}$, then the interior angle is 60$text{textdegree}$ and thus the regular polygon is a regular triangle which is also called an equilateral triangle.

b. Square (or regular quadrilateral)

c. The interior angle sum is given by $(n-2)180text{textdegree}$ with $n$ the number of sides of the polygon:

$$
(n-2)180=1260
$$

Divide both sides of the equation by 180:

$$
n-2=7
$$

Add 2 to both sides of the equation:

$$
n=9
$$

Thus the polygon is a nonagon.

d. A rhombus is a quadrilateral with perpendicular diagonals that bisect each other.

Result
2 of 2
a. Equilateral triangle
b. Square
c. Nonagon
d. Rhombus
Exercise 145
Step 1
1 of 3
42 of the 63 drinks are Coffee, while 21 of the drinks are dairy products.

The probability is the number of favorable outcomes divided by the number of possible outcomes:

$$
begin{align*}
P(text{Coffee})&=dfrac{text{# of favorable outcomes}}{text{# of possible outcomes}}=frac{42}{63}=frac{2}{3}
\ P(text{Dairy})&=dfrac{text{# of favorable outcomes}}{text{# of possible outcomes}}=frac{21}{63}=frac{1}{3}
end{align*}
$$

We need to assume that choosing a coffee drink is independent of choosing a dairy product drink. Use the $textbf{Multiplication rule}$ for independent events: $P(Acap B)=P(Atext{ and }B)=P(A)times P(B)$

$$
begin{align*}
P(text{Coffee and Dairy})&=P(text{Coffee})times P(text{Dairy})
\ &=frac{2}{3}times frac{1}{3}
\ &=frac{2}{9}
\ &approx 0.2222
\ &=22.22%
end{align*}
$$

Step 2
2 of 3
Use the $textbf{General addition rule}$ for any two events: $P(Atext{ or }B)=P(A)+P(B)-P(Atext{ and }B)$

$$
begin{align*}
P(text{Coffee or Dairy})&=P(text{Coffee})+P(text{Dairy})-P(text{Coffee and Dairy})
\ &=frac{2}{3}+frac{1}{3}-frac{2}{9}
\ &=1-frac{2}{9}
\ &=frac{7}{9}
end{align*}
$$

Use the $textbf{Complement rule}$: $P(A^C)=P(text{not }A)=1-P(A)$

$$
begin{align*}
P(text{Not Coffee nor Dairy})&=1-P(text{Coffee or Dairy})
\ &=1-frac{7}{9}
\ &=frac{2}{9}
\ &approx 0.2222
\ &=22.22%
end{align*}
$$

Result
3 of 3
Both: $frac{2}{9}approx 0.2222=22.22%$

Neither: $frac{2}{9}approx 0.2222=22.22%$

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Chapter 1: Exploring Algebraic and Geometric Relationships
Page 3: Questions
Page 64: Closure Activity
Chapter 2: Justification and Similarity
Page 71: Questions
Page 137: Closure Activity
Chapter 3: Probability and Trigonometry
Page 145: Questions
Page 202: Closure Activity
Chapter 5: Quadratic Functions
Page 259: Questions
Page 314: Closure Activity
Chapter 7: Proof and Conditional Probability
Page 371: Questions
Page 423: Closure Activity
Chapter 8: Polygons and Circles
Chapter 9: Modeling with Functions
Page 483: Questions
Page 537: Closure Activity
Chapter 10: Circles and More
Page 545: Questions
Page 592: Closure Activity
Chapter 12: Counting and Closure
Page 644: Questions
Page 701: Closure Activity