Secant, cosecant, and cotangent.

After sine, cosine, and tangent, there are only 3 more possible ratios to be made from a triangle. These last relations are the inverse of the respective functions, they are secant (sec), cosecant (csc), and cotangent (cot).



x = The angle x
O = Opposite side of the angle x
A = Adjacent side of the angle x
H = Hypotenuse

sin(x) = O/H
csc(x) = H/O

cos(x) = A/H
sec(x) = H/A

tan(x) = O/A
cot(x) = A/O