Question

What is the period and amplitude for `y=3 cos x`?

Answer 1

The period is `1` and the amplitude is `3`.

Explanation:

For a general cosine function of the form `Y = Acos(Bx)`, `A` is the amplitude (The maximum absolute value of the oscillation) and `B` is the period (meaning that the function completes one cycle every `(2pi)/B` interval).

This function has the amplitude `3`, giving an oscillation between `-3` and `3`, and the period `1`, giving the interval length of `2pi`.

Graphed, it looks like this:

graph{y = 3cosx [-10, 10, -5, 5]}