Question

How do you find the amplitude of a cosine function?

Answer 1

Discussed below.

Explanation:

We should have a cosine function to talk about.
I will use `A*costheta`.

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