Trig Identities Flashcards
1
Q
What is the basic trig identity?
A
sin^2 x + cos^2 x = 1
2
Q
What are the two identities that build off the basic trig identity?
A
1 + cot^2 x = cos^2 x
1 + tan^2 x = sec^2 x
3
Q
What are the sin sum identities?
A
sin(x +/- y) = sinX cosY +/- cosX sinY
4
Q
What are the cos sum identities?
A
cos(x +/- y) = cosX cosY -/+ sinX sinY
5
Q
What is the sin double angle identity?
A
sin2x = 2 * sinX * cosX
6
Q
What is the cos double angle identity?
A
cos2x = cos^2 X - sin^2 X
7
Q
What is the sin power reducing identity?
A
sin^2 X = (1 - cos2X) / 2
8
Q
What is the cos power reducing identity?
A
cos^2 X = (1 + cos2X) / 2
9
Q
What are the three side values of a 30-60-90 triangle?
A
xSQRT(3), x, 2x
10
Q
What are the three side values of a 45-45-90 triangle?
A
x, x, xSQRT(2)
