Investigating Relationships Between Sin & Cos Functions
With the arrow tool selected, click and drag the point (x, y) around the circle in a counterclockwise direction.
You will simultaneously see one full cycle of y = sin(x) traced in blue and one full cycle of y = cos(x) traced in red.
The degrees that are shown inside the circle correspond with the radian angle measures along the x-axis. For example, 90 degrees = pi/2 radians.