Use identities to write the expression as a single function of x or $$\theta$$
-$\sin ( x + 2 \pi )$
A) $- \cos x$
B) $\frac { \sqrt { 2 } } { 2 } \cos x - \frac { \sqrt { 2 } } { 2 } \sin x$
C) $\frac { \sqrt { 2 } } { 2 } \cos x + \frac { \sqrt { 2 } } { 2 } \sin x$
D) $\sin x$

Question

Quizplus · Accepted Answer

The identity $\sin(x + 2\pi) = \sin x$ is used because adding $2\pi$ to the angle $x$ in sine function does not change its value due to the periodicity of the sine function, which has a period of $2\pi$.

Use Identities to Write the Expression as a Single Function θ\thetaθ

Use Identities to Write the Expression as a Single Function $\theta$