# pre-cal

posted by
**ethan**
.

Simplify the given expression........?

(2sin2x)(cos6x)

sin 2x and cos 6x can be expressed as a series of terms that involve sin x or cos x only, but the end result is not a simplification.

sin 2x = 2 sinx cosx

cos 6x = 32 cos^6 x -48 cos^4 x

+ 18 cos^2 x - 1

I assume you are not talking abous sin^2 x and cos^6 x

cos 6x could be written 2 cos^2 3x -1

but that doesn't help much, either