What is the cosine curve?

The cosine curve is an up-down curve which starts at one and heads down until ? radians (180 degrees) and then heads up again. Plotting of the cosine of an angle against that angle measure results in a classic shape similar to a cosine curve.

Cosines and Sines are graphs of trigonometric functions, and can be produced in degrees or radians. The sine function is similar to that of the cosine, but it starts at 0, heads up to 1 by ?/2 radians (90 degrees) and then heads down to -1. The natural cosine and sine curves describe the horizontal and vertical coordinates of a point on the unit circle in relation to the counter-clockwise distance along the circle to the point from a reference point of intersection between circle and the horizontal axis.