SAT Math

Percent Change formula

Difference/initial • 100%

X is what percent of y

X = (P/100) • Y

Median

Middle value ordered by size

Mode

Most frequent

Standard Deviation

Average distance between mean and value

Range

Largest value - smallest value

C in a parabola

Y intercept

1 of 2 exclusive events

P(A) + P(B)

1 of 2 related events

P(A) + P(B) - P(A and B)

Probability of independent events

P(A) • P(B)

Probability of related events

P(A) • P(B/A)

(a+b)²

a² + 2ab + b²

(a-b)²

a² - 2ab + b²

(a+b)(a-b)

a² - b²

Discriminant of a quadratic

b² - 4ac

Positive Discriminant

2 unique real solutions

Zero Discriminant

1 unique real solution

Negative Discriminant

No unique real solutions

When do functions possibly get extraneous solutions

When raising to an even power

Exponential functions

Quadratic functions

Polynomial remainder theorem

When function is divided by x-a the remainder is p(a)

Pythagorean Triples

3-4-5

5-12-13

6-8-10

9-12-15

30-60-90 triangle

45-45-90 triangle

Sin(x) =

Cos(90-x)

How to get circle in standard form

Complete the square

Sum of roots

-b/a

Product of roots

c/a