00:01
The first thing to know about this problem is that cosecant of x is the same thing as the reciprocal of sign.
00:09
So it's 1 over sine of x.
00:11
So essentially, if we are not in the domain, isn't that what the question is, which of the following is not in the domain, that's any time that sine of x is equal to zero.
00:26
So if you think about the unit circle and we care about where sign equals, 0, that would be anytime the y coordinate equals 0.
00:36
So that happens at two places, either at 1 -0 or over here at negative -10.
00:43
And how do we get there? well, there's a couple ways.
00:46
You could go clockwise, and any time we go clockwise, that would be a negative angle, and doing pi radians would get us to this ordered pair of negative 1 -0.
00:57
So that should be one box that you check.
01:00
There's a little check box right there...