Six Trigonometric Functions
and Trigonometric Identities
Cos
x/r
Even
Inverse is 1/Sec
Sec
r/x
Even
Inverse is 1/Cos
Pythagorean Identities
Sin^2 + Cos^2 = 1
Tan^2 + 1 = Sec^2
Cot^2 -1 = Csc^2
Tan
y/x
Odd
Inverse is 1/Cot
Sin
y/r
Odd
Inverse is 1/Csc
Cot
x/y
Odd
Inverse is 1/Tan
Csc
r/y
Odd
Inverse is 1/Sin