How do you graph cos^2 (x)?

Oct 24, 2017

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

Explanation:

Note that:

$\cos 2 x = 2 {\cos}^{2} x - 1$

So:

${\cos}^{2} x = \frac{1}{2} \left(\cos 2 x + 1\right)$

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

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