Graph of y = cos x

The graph below shows the cosine wave in degrees.

When dealing with angles it is often necessary to work in radians. Whereby 360° = 2π radians.

Because of the cyclic nature of the wave it is possible to map the behaviour onto what is know as a quadrant diagram.

Please click the graph to show how this is built up.

The cosine function

1. This graph is continuous.

2. The range is

3. It has a period of 2

4. The shape is the same as the sine wave but displaced a distance of to the left on the horizontal axis. This is called a phase shift.