Hi

I'm having some problems seeing how they've come to an answer in the course book, here we go.

$\displaystyle sin^2x \ cos^2x = \frac{1}{4}\ sin^2(2x) $

and then through several stages, some skipped, we get

$\displaystyle =\frac{1}{8}\ (1-cos(4x)) $

Any help would be appreciated.

Thanks