Question

I'm getting confused with these Inverse Trig Functions:
sin^-1(-1/2)

So the answer is "-π/6" but shouldn't the answer be "11π/6"? Can someone explain this to me...

Answer 1

These are the same location on the unit circle (12pi/6 is 2pi). So it depends on the domain. Inverse trig functions always give the first quadrant values of the unit circle and the neighboring negative answers. Arccos does first and second, arcsin does first and fourth. And the values are contiguous.