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

Question

Quizplus · Accepted Answer

The expression $1 - 2 \sin ^ { 2 } 2 x$ can be rewritten using the double angle identity for cosine, which is $\cos 2\theta = 1 - 2\sin^2\theta$. By substituting $\theta$ with $2x$, we get $\cos 4x$, making option A correct.

Use an Identity to Write the Expression as a Single 1−2sin⁡22x1 - 2 \sin ^ { 2 } 2 x1−2sin22x

Use an Identity to Write the Expression as a Single $1 - 2 \sin ^ { 2 } 2 x$