Question

why tan^{-1} (-sqrt{3}) = -60 degree?

Answer 1

Given equation is wrong.... -1 can't be in the power

Answer 2

@goformit100 its arctan..

Answer 3

ok.

Answer 4

i know it = 60, but really dont know why

Answer 5

is your concern specifically on the sign. I.e Why -60 and not +60? or you just don't know why it's -60 as it is?

Answer 6

is what I did in the pic right?

Answer 7

yes, but it's like circular reasoning. You had to know the angle is -60 first before you can do the calculation.

Answer 8

the questions is how did you know it's negative -60 at the first place?

By your argument, I can do,
tan(120) = -sqrt(3), so why not arctan(-sqrt(3)) = 120?