Find the exact value without using a calculator.
-$$\sin \frac { 3 \pi } { 4 }$$
A) $\frac { 1 } { 2 }$
B) $- \frac { 1 } { 2 }$
C) $- \frac { \sqrt { 2 } } { 2 }$
D) $\frac { \sqrt { 2 } } { 2 }$

Question

Quizplus · Accepted Answer

The exact value of $\sin \frac { 3 \pi } { 4 }$ is $\frac { \sqrt { 2 } } { 2 }$, because $\frac { 3 \pi } { 4 }$ is in the second quadrant where sine is positive, and it corresponds to a 45-degree angle in standard position, whose sine is $\frac { \sqrt { 2 } } { 2 }$.

Find the Exact Value Without Using a Calculator sin⁡3π4\sin \frac { 3 \pi } { 4 }sin43π​

Find the Exact Value Without Using a Calculator $\sin \frac { 3 \pi } { 4 }$