Evaluate without using a calculator, leaving the answers in exact form. $\sin \frac { 3 \pi } { 4 }$
A) $\frac { \sqrt { 2 } } { 2 }$
B) $\frac { 1 } { 2 }$
C)1
D)0
E) $\frac { 3 } { 2 }$

Question

Quizplus · Accepted Answer

$\sin \frac { 3 \pi } { 4 }$ is equivalent to $\sin(135^\circ)$, which is in the second quadrant where sine is positive. The reference angle for $135^\circ$ is $45^\circ$, and $\sin(45^\circ) = \frac{\sqrt{2}}{2}$.

Evaluate Without Using a Calculator, Leaving the Answers in Exact sin⁡3π4\sin \frac { 3 \pi } { 4 }sin43π​

Evaluate Without Using a Calculator, Leaving the Answers in Exact $\sin \frac { 3 \pi } { 4 }$