#### Answer

Please see below.

#### Work Step by Step

The red graph is the graph of $y=0.8 \sin \frac{x}{2}$, and the blue graph is the graph of $y=0.8 \sec \frac{x}{2}$.
The period of both functions are the same and equal $\frac{2\pi }{\frac{1}{2}}=4\pi$.