Question

tan^-1 (-1)

Answer 1

-pi/4

Answer 2

wolfram it

Answer 3

So what's this mean? This is value you get from tangent of an angle where tan(x)=-1. So let's take it apart:

sin(x)/cos(x) have to have the same value, but opposite signs in order for this to be true. So where does this happen? It doesn't happen at 45 degrees, since that will be sqrt(2)/2 divided by sqrt(2)/2 which is +1. So we have to go 90 degrees in any direction from 45 degrees depending on what your domain is.

Answer 4

The answer is -45 degrees.