Question

Question #a0abc

Answer 1

Proof below

Explanation:

To me this looks more like a proving question than a solving question (because as you'll see if you graph it, it's always equal)

The proof:
`1-2cos^2x+2cos^4x=1-2cos^2x+cos^4x+cos^4x`
`=1-2cos^2x+(cos^2x)^2+cos^4x`
`=(1-cos^2x)^2+cos^4x`
`=(sin^2x)^2+cos^4x`
`=sin^4x+cos^4x`