Simplify the given expression algebraically. $\cos \left( \frac { \pi } { 2 } + x \right)$
A) $\cos x$
B) $- \sin x$
C) $\sin x$
D)1
E) $- \cos x$

Question

Quizplus · Accepted Answer

Using the trigonometric identity $\cos(\alpha + \beta) = \cos \alpha \cos \beta - \sin \alpha \sin \beta$, and knowing that $\cos(\frac{\pi}{2}) = 0$ and $\sin(\frac{\pi}{2}) = 1$, we can simplify $\cos(\frac{\pi}{2} + x)$ to $-\sin x$.

Simplify the Given Expression Algebraically cos⁡(π2+x)\cos \left( \frac { \pi } { 2 } + x \right)cos(2π​+x)

Simplify the Given Expression Algebraically $\cos \left( \frac { \pi } { 2 } + x \right)$