Chapter 8.4, Problem 6E

In Problems 1–8, by using only the unit circle definitions of the sine and cosine functions (see page 512), find the solution set of each equation or inequality on the given interval. (If necessary, review Section 1.3).

6.     $\left|\cos x\right|=\frac{\sqrt{2}}{2}\text{on}\left[0,2\pi \right]$