Answer
please see image
Work Step by Step
1. Start with the parent function $f(x)=\cos x$
(Graph:red dashed , amplitude 1, period $ 2\pi$)
If plotting by hand, use Table 2 on page 420 to plot 13 points on $[0,2\pi]$,
connected with smooth line)
2. The graph of $-2+\cos x=f(x)-2$ is obtained by
shifting f(x) downwards by two units
Graphing utility used: online calculator desmos.com.
The "wrench" button is used to set viewing window settings:
radians, step $\pi/2$, ... (see image below)
The accompanying table gives a sufficient number of points for graphing by hand.