Find the exact value of the expression.
-$\sin 945 ^ { \circ }$
A) $- \frac { 1 } { 2 }$
B) $- \frac { \sqrt { 2 } } { 2 }$
C) $- \frac { \sqrt { 3 } } { 2 }$
D) $2 \sqrt { 3 }$

Question

Quizplus · Accepted Answer

$\sin 945^\circ$ can be simplified by finding a coterminal angle within the first cycle of the unit circle (0 to 360 degrees). Subtracting 360 degrees repeatedly from 945 degrees until it falls within this range gives us $\sin 945^\circ = \sin (945 - 2 \times 360)^\circ = \sin 225^\circ$. The sine of 225 degrees, which is in the third quadrant where sine is negative, equals $-\frac{\sqrt{2}}{2}$.

Find the Exact Value of the Expression sin⁡945∘\sin 945 ^ { \circ }sin945∘

Find the Exact Value of the Expression $\sin 945 ^ { \circ }$