ACT Math Reference sheet

Standard Form

Ax+By+C=0

Slope Intercept Form

y=mx+b

Point Slope Form

y-y1= m(x-x1)

Slope

m=\frac{y2-y1}{x2-x1}

General form of a quadratic

ax^2+bx+c=0

Quadratic Formula

x=\frac{-b\pm\sqrt{b^2-4ac}}{2a}

Midpoint Formula

(\frac{x1+x2}{2}, \frac{y1+y2}{2})

Distance Formula

d=\sqrt{(x2-x1)² + (y2-y1)²}

Area of a triangle

A=\frac{1}{2}bh

Area of a parallelogram

A=bh

Area of a trapezoid

A=\frac{1}{2}(b1+b2)h

Volume of a prism

V=Bh

Surface area of a prism

SA=2B+Ph

Volume of a circular cylinder

V=\pi r^2 h

Volume of a Pyramid

V=\frac{1}{3}Bh

Volume of a Circular Cone

V=\frac{1}{3}\pi r^2 h

Volume of a Sphere

V=\frac{4}{3}\pi r^3

Degree Measure of a regular polygon

\frac{180(n-2)}{n}

Sum of Degree Measures in a polygon

180(n-2)

Center Radius Form of a circle

(x-h)²+(y-k)²=r²

Area of a Circle

A=\pi r^2

Circumference of a circle

C=2\pi r

Pythagorean Theorem

a²+b²=c²

Trig Ratios

SohCahToa

Arithmetic Sequence

An=A1+(n-1)d

Sum of an arithmetic series

Sn=\frac{n}{2}(a1+a_n)

Simple Interest

I=prt

Compound Interest

A=p(1+\frac{r}{n})^{nt}

Distance, rate, time

D=rt

Direct variation

Y= kx. K= variation constant

Cos 0

1

Sin 30

½

Cos 30

sqrt 3/2

Tan 30

Sqrt 3/3

Sin 45

Sqrt 2/2

Cos 45

Sqrt 2/2

Tan 45

1

Sin 60

Sqrt 3/2

Cos 60

½

Tan 60

Sqrt 3

Sin 90

1

Cos 90

0

Tan 90

Undefined