cofunction
/koʊˈfʌŋkʃən/
noun
- In trigonometry, one of a pair of functions (such as sine and cosine, or tangent and cotangent) that are equal when the angles are complementary (add up to 90 degrees).
- In math class, we learned that sine and cosine are cofunctions because sin(30°) equals cos(60°).
- To solve the problem, she used the cofunction relationship between tangent and cotangent.
- The teacher explained that the cofunction identity helps simplify trigonometric expressions.