find all solutions on 0 is greater than or equal to theta < 2pi
cos theta= 2sqrt3/3
4-1/2sin theta= (-16+sqrt3)/4
3(sqrt3)= -3cot theta
-2=-1-2sin theta
cos theta= 2sqrt3/3
4-1/2sin theta= (-16+sqrt3)/4
3(sqrt3)= -3cot theta
-2=-1-2sin theta