Answer
$y = -4~sin~x$
We can see the graph below.
The period is $2\pi$.
The amplitude is 4.
Work Step by Step
$y = -4~sin~x$
When $x = 0$, then $y = -4~sin~0 = 0$
When $x = \frac{\pi}{2}$, then $y = -4~sin~\frac{\pi}{2} = -4$
When $x = \pi$, then $y = -4~sin~\pi = 0$
When $x = \frac{3\pi}{2}$, then $y = -4~sin~\frac{3\pi}{2} = 4$
When $x = 2\pi$, then $y = -4~sin~2\pi = 0$
We can see the graph below.
The period is $2\pi$
The amplitude is 4
