Answer
$$y=2\csc \frac{2}{3}x$$
Work Step by Step
Please note that a cosecant function $y=A\csc Bx$ has range $(- \infty, -|A|] \cup [|A|, \infty )$ and period $\frac{2\pi }{B}$.
According to the information given in the question, we find that this is a cosecant function with $|A|$=2 and $B=\frac{2\pi }{3\pi }=\frac{2}{3}$. Thus,$$y=2\csc \frac{2}{3}x.$$
