How to find the value of x if #sec x = -5#?
We rewrite the secant function and do some algebric manipulation.
We take the arccosine of both sides
And evaluate that on a calculator, it comes out to approximately
The arccosine has a proper range so it outputs every value uniquely (We know it only outputs values on the range of
But since we know that
And that isn't all done, since there is another angle, this time on the third quadrant with the same cosine, we know that
Which leaves us