Question

What is the amplitude of `y = -2cos(4x+pi/3)`?

Answer 1

The amplitude is `2` units.

Explanation:

The modulus of the number in front of your `cos` function gives you the amplitude or maximum height reached in the negative OR positive direction. In this case is `-2` meaning that your cosine will oscillate between `-2` and `2`.

Graphically:
graph{-2cos(4x+pi/3) [-10, 10, -5, 5]}