Well, cos = 1/sec so we have that , which leads us to which implies that . Where in do we find such an angle? is the only one I can think of.Originally Posted bymacca101

The reason that just taking the inverse tangent won't work is that you will get a list of possibles and the answer is buried in there. However, youcoulddo the inverse tangent and inverse secant and compare the two lists...(rather like what I did with the sine and cosine values.)

-Dan