Question

The problem says:

Solve the equation on the interval 0 ≤ θ < 2π.

Solve the equation on the interval 0 ≤ θ < 2π.

2 cos^2 x - 1 = 0
So far I have:

2cos^2x=1
cos^2x=1/2
cosx= +/- sqrt(1/2)

After this I don't know what to do

Answer 1

for what values of x, is cos x = 1/2 or -1/2 where 0<x<2pi ?

Answer 2

sqrt(1/2) similar by 1/2 * sqrt(2)