#### Cofunctions are two trigonometric functions whose complementary input angles produce equal output. When we look at the actual math behind this, remember that we are working with co-functions, so if you are working with sine; you will also be working with cosine. In this section you will be asked to determine the cofunction, simplify operations, or evaluate a small system. Students should already be familiar with sine, cosine, tangent, cotangent, secant, and cosecant.

What Are Cofunctions?
A function 'f' is the cofunction of a function 'g'. So, f = g whenever A and B are complementary angles. This description naturally applies to trigonometric functions.
The prefix "co-" can originate already in Edmund Gunter's Canon triangulorum.
What are Cofunctions in trigonometry?
The cofunction identities show the association amongst cosine, sine, cotangent, Tangent, cosecant, and secant. The worth of a trigonometric function of an angle equals the value of the cofunction of the complement.
A recollection from geometry that an accompaniment is apparent as two angles whose sum is 90° These worksheets explain how to solve for cofunctions and how to simplify expressions containing cofunctions. These worksheets will help you learn how to simplify and find the values of different trigonometric functions.