### Home > PC > Chapter 8 > Lesson 8.2.2 > Problem8-96

8-96.

Use your results from the previous problem to show that $\left(\sin x + \cos x\right)^{4} − \left(\sin x − \cos x\right)^{4} = 4 \sin\left(2x\right)$.

The answer to the previous problem was:
$8ab\left(a^{2} + b^{2}\right)$
Substitute $\sin x$ for '$a$' and the $\cos x$ for '$b$'.

Show all of your work to get the following answer: $4\sin\left(2x\right)$