Fundamental Trigonometric Identities
Reciprocal Identities
sin = 1/csc
cos = 1/sec
tan = 1/cot
csc = 1/sin
sec = 1/cos
cot = 1/tan
Quotient Identities
tan = sin/cos
cot = cos/sin
Pythagorean Identities
sin^2 + cos^2 = 1
1 + tan^2 = sec^2
1 + cot^2 = csc^2
Even Odd Identities
sin(-x) = -sin x
cos(-x) = cos x
tan(-x) = -tan x
sec(-x) = sec x
csc(-x) = -csc x
cot(-x) = -cot x