I am stuck on these two problems. I have absolutely no idea how to get them. any help would be greatly appreciated.

1. $\displaystyle 1-4sin^2xcos^2x

$

2. $\displaystyle cos^22x-cos^2x=sin^2xtan^2x$ I just think you have to solve the identity

the answer has to be simplified to a single term.

Thank you.