Use the fundamental identities to simplify the expression.
-$\cos \theta - \cos \theta \sin ^ { 2 } \theta$
A) $\sin \theta$
B) $\cos ^ { 3 } \theta$
C) $\sec ^ { 2 } \theta$
D) $\tan ^ { 2 } \theta$

Question

Quizplus · Accepted Answer

The expression can be simplified using the Pythagorean identity $\sin^2\theta + \cos^2\theta = 1$, which allows us to rewrite $\cos\theta - \cos\theta\sin^2\theta$ as $\cos\theta(1 - \sin^2\theta)$. Substituting $\cos^2\theta$ for $1 - \sin^2\theta$ gives us $\cos\theta \cdot \cos^2\theta = \cos^3\theta$.

Use the Fundamental Identities to Simplify the Expression cos⁡θ−cos⁡θsin⁡2θ\cos \theta - \cos \theta \sin ^ { 2 } \thetacosθ−cosθsin2θ

Use the Fundamental Identities to Simplify the Expression $\cos \theta - \cos \theta \sin ^ { 2 } \theta$