What is another word for cofunctions?
Pronunciation: [kəfˈʌŋkʃənz] (IPA) 
Cofunctions are two trigonometric functions that have complementary angles. The most common synonym for cofunctions is complementary angles. The term complementary angles refers to two angles whose sum is 90 degrees. Other synonyms for cofunctions include inverse functions and reciprocal functions. The term inverse functions is often used to refer to functions that undo each other's effect. Reciprocal functions, on the other hand, refer to the inverse of a function. Cofunctions are important in trigonometry because they are used to simplify expressions and to find values of trigonometric functions that might not be so easy to calculate otherwise.
