Main content

### Course: Trigonometry > Unit 2

Lesson 1: Unit circle introduction# Unit circle

Learn how to use the unit circle to define sine, cosine, and tangent for all real numbers. Created by Sal Khan.

## Want to join the conversation?

No posts yet.

If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Main content

Learn how to use the unit circle to define sine, cosine, and tangent for all real numbers. Created by Sal Khan.

No posts yet.