Question

How do you graph `y=2cos3x`?

Answer 1

Graph it to see what it looks like.

Explanation:

For a cosine function of the form `y = Acos(Bx)`, `A` is the amplitude (maximum absolute value), and `B` is the number of cycles completed every `2pi` interval (or one cycle every `(2pi)/B` interval).

For this function, the amplitude is `2`, giving the oscillation between `-2` and `2`, and the cycle period is `(2pi)/3 ~~ 2.09`.

The graph looks like this:

graph{2cos(3x) [-4, 4, -2.5, 2.5]}