Question

How do you sketch `f(x)=cos^2(x)`?

Answer 1

f(x) = `cos^2`x also means f(x) = `(cosx)^2`

SO whatever the value you get from the function f(x) = cosx, you square it.

i.e. the maximum point of this graph is `1^2` which is 1 itself and also all the negative values when squaring becomes positive so the range is `0<=f(x) <= 1`.

graph{(cosx)^2 [-10, 10, -5, 5]}