# How do you find the amplitude of a cosine function?

Jul 21, 2018

Discussed below.

#### Explanation:

We should have a cosine function to talk about.
I will use $A \cdot \cos \theta$.

A plot of the basic cosine has a max value of 1 and a minimum of -1. Remember that a plot of the cosine is a wave. The magnitude of that wave is 1.

So for any value of $\theta$, "the amplitude of the cosine function " A*costheta = |A|.

I hope this helps,
Steve