## The Sine Function and The Unit Circle

This picture shows an animation of the sine function and its relation to the unit circle. The
function *y=sin(t)* is related to the unit circle in the following manner: The angle
*t* (blue angle measure) is the *t* coordinate in the ordered pair *(t, sin(t))*. The
value of the sine is the displacement of the red dot from the *t*-axis.
The function is 2 π periodic.

## The Cosine Function and The Unit Circle

This picture shows an animation of the cosine function and its relation to the unit circle. The
function *y=cos(t)* is related to the unit circle in the following manner: The angle
*t* (blue angle measure) is the *t* coordinate in the ordered pair *(t, cos(t))*. The
value of the cosine is the displacement of the red dot from the *y*-axis.
The function is 2 π periodic.

close