I'm thinking I may not understand what is a possible solution of a problem and what not. The interval for all of my problems is 0 to 2pi. So I suppose that if my answer was Sec=2, that I'd convert it to Cos, then it would be all of the angles that x = 1/2. I think I have this much right, my confusion is when there are two answers, such as the one listed above, and say sec = -1. What do I do here?