Use an identity to write the expression as a single trigonometric function or as a single number.
-$$\cos ^ { 2 } 4 x - \sin ^ { 2 } 4 x$$
A) $2 \sin 4 x$
B) $\frac { 1 } { 2 } \sin 16 x$
C) $\cos 4 x$
D) $\cos 8 x$

Question

Quizplus · Accepted Answer

This expression can be simplified using the double angle identity for cosine, which is $\cos(2\theta) = \cos^2(\theta) - \sin^2(\theta)$. By applying this identity with $\theta = 4x$, the expression simplifies to $\cos(8x)$.

Use an Identity to Write the Expression as a Single cos⁡24x−sin⁡24x\cos ^ { 2 } 4 x - \sin ^ { 2 } 4 xcos24x−sin24x

Use an Identity to Write the Expression as a Single $\cos ^ { 2 } 4 x - \sin ^ { 2 } 4 x$