I understand what to do (for the most part), but need a suggestion or two in how to approach these problems:

Simplify and reduce:

$\displaystyle (sinx + cscx)(sin^2x + csc^2x-1)$

Factor and reduce:

$\displaystyle sin^4 - cos^4$

The answer to the first one is $\displaystyle sin^3 . cos^3$ but i have no idea how to solve it.. ive tried it a hundred different ways.

for the second one, how would I start?