# Pre-Calculus

posted by
**Maria** on
.

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.