# Sine

Sine is a trigonometric function describing the ratio between the opposite side and the hypotenuse in a right triangle. As a function it is usually abbreviated sin.

## Sine Graph

The basic sine graph is as follows:

x values y values
0 0
π/2 1
π 0
3π/2 -1
0

That would be a full period of the graph - as 2π radians is equivalent to one circle. The graph continues in that pattern.

## Relationship to cosine and cosecant

A mathematical identity involving sine is:

$\sin \theta = \cos \left(\frac{\pi}{2} - \theta \right) = \frac{1}{\csc \theta}\,$