The cosecant function has a domain of all real numbers except for those where sinx = 0 or x equals any odd multiple of π/2. In other words, cscx is undefined at x = π/2, 3π/2, 5π/2, etc.

The graph of the cosecant function looks like this: The domain of the function y = csc ( x ) = 1 sin ( x ) is all real numbers except the values where sin ( x ) is equal to 0 , that is, the values π n for all integers n . The range of the function is y ≤ − 1 or y ≥ 1 .