Why do you have +/- 180?
As to your other answer, where else is cos(Beta) = (1/2)? That will be the base of your 2nd answer. Hint: 4th quadrant.
4cosBeta=1+2cosBeta
2cosBeta=1
cosBeta=1/2
60 degrees +/- 180--is this right?
I know there should be another answer, but I'm not sure if it needs to be 240 +/-180 or 120 +/- 180. I don't know how to tell if it's added to 180 or subtracted, could you please explain??
2 answers
330 degrees?