Question

How do you graph `cos^2 (x)`?

Answer 1

Like `cos x` but half the size and shifted up into range `[0, 1]` instead of `[-1, 1]`

Explanation:

Note that:

`cos 2x = 2cos^2 x - 1`

So:

`cos^2 x = 1/2(cos 2x+1)`

So this will be a sinusoid like `cos x` but double the frequency (i.e. half the period) and with range `[0, 1]` instead of `[-1, 1]`.

graph{(cos(x))^2 [-5, 5, -2.5, 2.5]}