What is the domain and range of y=csc xy=cscx?

1 Answer
Dec 20, 2017

Domain of y=csc(x)y=csc(x) is x\inRR, x\ne pi*n, n\inZZ.
Range of y=csc(x) is y<=-1 or y>=1.

Explanation:

y=csc(x) is the reciprocal of y=sin(x) so its domain and range are related to sine's domain and range.

Since the range of y=sin(x) is -1<=y<=1 we get that the range of y=csc(x) is y<=-1 or y>=1, which encompasses the reciprocal of every value in the range of sine.

The domain of y=csc(x) is every value in the domain of sine with the exception of where sin(x)=0, since the reciprocal of 0 is undefined. So we solve sin(x)=0 and get x=0+pi*n where n\inZZ. That means the domain of y=csc(x) is x\inRR, x\ne pi*n, n\inZZ.