# How do you solve #cos^2theta=1#?

##### 1 Answer

Nov 25, 2016

First take the square root of both sides.

#sqrt(cos^2theta) = sqrt1#

Simplify, and don't forget the

#costheta = +-1#

Now think back to the unit circle and find the values where

#theta = 0, pi#

Those are the answers in the range from

#theta = 2pin, pi + 2pin#