CPM Homework Help : PC3 Problem 13-28

Factor each of the following expressions.

Hint:

Remember that a difference of two squares has a special factoring pattern.

$a^{2} − b^{2} = \left(a − b\right)\left(a + b\right)$

$1-\sin^2\left(x\right)$
Hint (d):
Think of $\sin^2\left(x\right)$ as one big variable (like $w^{2}$ ).