From the graph,
[tex]f(\frac{\pi}{2})=2[/tex]From the graph, the values of x for which f(x) is zero is,
[tex]x=-2\pi,-\pi,0,\pi,2\pi,\ldots.[/tex]The rangge of a function is defined the possible y values of the function.
From the graph, the range is [-2,2].