There was a LaTex error that I had to fix, but with the new equation the angle is 45 degrees. So, would it be pi/4, 3pi/4, 5pi/4, and 7pi/4??
Regarding your answer, not quite... according to your equation, the cos of theta is positive, so it can't be in all 4 quadrants. Cosine is only positive in quadrants I and IV. However, the reference angle is 45 degrees (or pi/4) so you've got the right answers in there. It's pi/4 and 7pi/4.