Trig identities Flashcards
1
Q
Pythagorean identity
A
sin^2 x + cos^2 x = 1
2
Q
Pythagorean identity w/ tan
A
tan^2 x + 1 = sec^2 x
3
Q
Pythagorean identity w/ cot
A
1 + cot^2 x = csc^2 x
4
Q
Addition formula for sin
A
sin(a + b) = sin a cos b + cos a sin b
5
Q
subtraction formula for sin
A
sin(a - b) = sin a cos b - cos a sin b
6
Q
addition formula for cos
A
cos(a + b) = cos a cos b - sin a sin b
7
Q
subtraction formula for cos
A
cos(a - b) = cos a cos b + sin a sin b
8
Q
addition formula for tan
A
tan(a + b) = (tan a + tan b) / (1 - tan a tan b)
9
Q
subtraction formula for tan
A
tan(a + b) = (tan a - tan b) / (1 + tan a tan b)
