Sin and Cos on the Unit Circle

Author:
bboettcher
Moving the point labeled "move" will allow you to change the value of the angle, Θ. The point is always dependent upon the unit circle (c) and the horizontal and vertical sides of the triangle will display the value of cos Θ and sin Θ, respectively.
At what values [0°, 360°) are sin Θ and cos Θ equivalent? In this applet, the angles are never shown as negative values. Identify what functions could be negative and when this should happen for each. At what points do either of the functions equal 1 or 0? Give your best explanation as to why these functions might be equal to one or zero on the unit circle.