Evaluate the Trigonometric Function Using Its Period as an Aid $\sin \frac { 3 \pi } { 4 }$

Multiple Choice

Evaluate the trigonometric function using its period as an aid.​ $\sin \frac { 3 \pi } { 4 }$ ​

A) $\sin \frac { 3 \pi } { 4 } = \infty$
B) $\sin \frac { 3 \pi } { 4 } = - \sqrt { 2 }$
C) $\sin \frac { 3 \pi } { 4 } = - \frac { \sqrt { 2 } } { 2 }$
D) $\sin \frac { 3 \pi } { 4 } = \sqrt { 2 }$
E) $\sin \frac { 3 \pi } { 4 } = \frac { \sqrt { 2 } } { 2 }$