### Home > APCALC > Chapter 10 > Lesson 10.1.2 > Problem10-23

10-23.

Use the trigonometric identity $\cos(2x) = 2\cos^2(x) - 1$ to rewrite each of the expressions below. Homework Help ✎

1. $\cos^2(x)$

$2\cos^2(x)=\cos(2x)+1$

1. $\sin^2(x)$

$\cos^2(x)=1-\sin^2(x)$

$\cos(2x)=2(1-\sin^2(x))-1$

Now solve for $\sin^2(x)$.