Question

2 cos 2θ − 1 = 0

find all solutions of the equation and Find the solutions in the interval [0, 2π)

Answer 1

x = cos2θ

2x-1=0
x must equal 1/2

cos2θ= 1/2

cos(2*pi/6)=1/2
cos(2*-pi/6) = 1/2

Answer 2

theta = pi/6 and -pi/6
.. i think.. did it quick