Answer
$y=\csc{x}$
Work Step by Step
The given graph could either be the basic secant function or the basic cosecant function.
The given graph has the vertical asymptotes $x=-2\pi, -\pi, 0, \pi, 2\pi$.
Since cosecant is the reciprocal of sine, and since the sine function is equal to $0$ for $x=-2\pi, -\pi, 0, \pi, 2\pi$, then the cosecant function is undefined when $x=-2\pi, -\pi, 0, \pi, 2\pi$.
Therefore ,the given graph must be the graph of the cosecant function.
