# Trig unit circle review

CCSS Math: HSF.TF.A.2
Review the unit circle definition of the trigonometric functions.

## What is the unit circle definition of the trigonometric functions?

The unit circle definition allows us to extend the domain of sine and cosine to all real numbers. The process for determining the sine/cosine of any angle $\theta$ is as follows:
1. Starting from $(1,0)$, move along the unit circle until the angle that is formed between your position, the origin, and the positive $x$-axis is equal to $\theta$.
2. $\sin(\theta)$ is equal to the $y$-coordinate of your point, and $\cos(\theta)$ is equal to the $x$-coordinate.
The other trigonometric functions can be evaluated using their relation with sine and cosine.
$\sin(50^\circ)=$