# Praxis 5161 Math Content Knowledge

Percentage Formula
change/originalx100

MADSPM
Rules for exponents
Multiply(add)
Divide(subtract)
Power(multiply)

Slope Intercept Form
Y=mx+b

Point Slope Form
y-y₁=m(x-x₁)

Quadratic Equation
-b±√b²−4ac)/2a

Discriminant
b²−4ac
<0 no roots >0 2 real roots
=0 1 real root

Distance between two points
√(x₁−x₂)²+(y₁−y₂)²

Midpoint
[x₁+x₂÷2,y₁+y₂÷2]

Volume of a right cylinder
πr²h

Volume of a sphere
4/3πr³

Surface area of a sphere
4πr²

Volume of a right cone
1/3πr²h

Surface area of a right cone
πr×side

ART FORMULA
I=art
I=interest
A=amount
R=rate
T=time

Discount formula
Cost(rate)

Distance
Speed(time)

Diameter

Area of a circle
πr²

Perimeter of a rectangle
2(l+w)

Average
Sum of terms/total number of terms

Average speed
Total distance/total time

Probability
Desired outcomes/total outcomes

SOHCAHTOA
sin=opp/hyp
cos=adj/hyp
tan=opp/adj

Arc length
n/360(2πr)

Area of a sector
n/360(πr²)

Pythagorean theorem
a²+b²=c²

Area of a rectangle
L(w)

Area of a triange
½bh

Perimeter of a circle
(Circumference)
2πr

Area of a trapezoid
½h(b₁+b₂)

Area of a square

Continuous compounding interest
B=Peʳᵗ
B=final balance
P=principal deposit
r=interest rate
t=time

Compounding interest annually
B=P(1+r)ᵗ
P=principal
r=annual interest rate
t=time
B=ending balance wanted

Area of a cube
6×side²

Volume of a cube
side³

How to find degree measurement of an interior angle
180(x-2)/x