In this activity, you’ll use the unit circle to plot the values for the sine and cosine functions on a coordinate plane. Explore the relationship between the unit circle and the sine and cosine functions using this simulation.

Set up the activity by selecting Radians, Special Angles, and Labels.

Part A
In the simulation, select the sin button. Then move the red point around the unit circle. Notice what happens to the values of x, y, and sin(0) as the point moves around the circle.

Consider the patterns revealed by the unit circle. Use these patterns to plot the points of the sine function.