Answer
$y = 3~sin~\pi x$
We can see the graph below.
The period is $2$
The amplitude is 3
Work Step by Step
$y = 3~sin~\pi x$
When $x = 0$, then $y = 3~sin~0 = 0$
When $x = \frac{1}{2}$, then $y = 3~sin~\frac{\pi}{2} = 3$
When $x = 1$, then $y = 3~sin~\pi = 0$
When $x = \frac{3}{2}$, then $y = 3~sin~\frac{3\pi}{2} = -3$
When $x = 2$, then $y = 3~sin~2\pi = 0$
We can see the graph below.
The period is $2$
The amplitude is 3