convert all to sin and cos and simplify
1/cos^2 = 4sin^2/cos^2
multiply both sides by cos^2, simplipies to sin^2=1/4
arc sin of +/- sqrt 1/4 = pi/6 and (-pi/6 degrees) <- not in 0 to 2pi
going to 2pi we probably will need to add pi to those for the other values
7pi/6 and 5pi/6 and pi/6 from above would be the three answers
