# Relationship Between Unit Circle and Trigonometric Functions

- Author:
- Bridget

1) Check the checkbox for "Point F" or "Point G".
2) Drag Point C around the unit circle and notice what happens as the angle changes.
3) Check the function created by the trace of Point F or Point G by checking "sin(x)" box for the sin(x) function and "cos(x)" for the cos(x) function.
To use the animation, click on the "play" symbol in the lower lefthand corner.
To turn the animation off, click on the "pause" symbol that replaced the "play" symbol.
Erase the trace by clicking the "Trace" button.

Questions:
As Point C moves about the circle, what happens to Point F? Point G?
Which function is displayed by the Trace of Point F?
Which function is displayed by the Trace of Point G?
Why is the x coordinate of C= cos(alpha)?
Why is the y coordinate of C= sin(alpha)