Find all solutions to the equation in the interval [0, 2pi)
cos4x-cos2x=0
So,this is what i've done so far:
cos4x-cos2x=0
cos2(2x)-cos2x
(2cos^2(2x)-1)-(2cos^2(x)-1)
No idea what to do next.
1 answer
http://answers.yahoo.com/question/index?qid=20080413170208AAL5ESb