#### Answer

$y = -5~sin~\frac{x}{3}$
We can see the graph below.

#### Work Step by Step

$y = -5~sin~\frac{x}{3}$
When $x = 0$, then $y = -5~sin~0 = 0$
When $x = \frac{3\pi}{2}$, then $y = -5~sin~\frac{\pi}{2} = -5$
When $x = 3\pi$, then $y = -5~sin~\pi= 0$
When $x = \frac{9\pi}{2}$, then $y = -5~sin~\frac{3\pi}{2} = 5$
When $x = 6\pi$, then $y = -5~sin~2\pi = 0$
We can see the graph below.