Cosine Box


Cosine Function

The figure shows a definition of cosine function.
The unit circle is the circle with its center at the origin and a radius of 1. Angle x is formed by rotating OA about the origin to OP. Then the x-coordinate of point P is cos x.

Applet

Input an angle(degrees),
then press enter key or click "Start" button.

Activity

Using the applet, find angle x that satisfies
  1. cos x=0.766
  2. cos x=-0.34
  3. cos x=0.50
  4. cos x=-0.68