Somebody sure doesn't like you guys very much. A weak joke. I think the best you can do to start with is graph this relationship. The best I can do is get an answer that is somewhere around 145 degrees. - 61 degrees, - 214 degrees and 255 degrees.
If you are intended to solve this any other way by using the double angle formulas as I started to get above and sin(x) or cos(x) I would take the 0 and hope to make it up some other way.
The domain is between -360 and plus 360. The range is between +/- 1.