Click here to view the embedded video.

A detailed tutorial on identifying the cofunction. Step by step tutorial including several examples of how to identify the cofunction for reference.

In math, we say that a function f is a cofunction of a function g if f(A) = g(B), and A and B are complimentary angles. Cofunctions are very often used with trigonometric functions like sine, cosine, and tangent. If you write a function in terms of its cofunction, it can make it easier to solve certain equations.