# Precalculus

### Topics

Missions recommend what to learn next, help you remember what you’ve learned by mixing skills, and save your progress.

Sign up### Staff picks

### Get Started

The inverse trigonometric functions

Learn about the inverse functions of sine, cosine, and tangent, and how they are defined even though the functions are not really invertible. These functions will be very helpful when you will solve trigonometric equations.

Start learningTable of contents