Trigonometry

Trigonometry is the study of triangles (relationships between lengths and angles of triangles). In this section we will breifly go over some things that you may have forgotten about trigonometry that you might find useful.

Basics:

Consider the above right angle triangle.

Let $\theta$ represent the angle at A

Then,

$sine \theta = {opposite \over hypotenuse}$ $cosine \theta = {adjacent \over hypotenuse}$

Now consider the following diagram of a unit circle:

The line from the origin to any point on a unit circle is going to have the coordinate value of $(cos \theta, sin \theta)$. This is because the hypotenuse will have a value of 1.