How do you solve #Cos^2 x - 1/2 = 0# over the interval 0 to 2pi?
First, take the half over to the other side to get:
We now need to find the inverse of this.
If we look at the graph of
We should expect two answers.
So we know at least
From the symmetry of the graph the second value can be obtained by
Thus, within the region,