Evaluate the cosine of the angle without using a calculator.
$330 ^ { \circ }$
A) $\frac { \sqrt { 2 } } { 2 }$
B) $- \frac { \sqrt { 2 } } { 2 }$
C) $\frac { \sqrt { 3 } } { 2 }$
D) $\frac { 1 } { 2 }$
E) 0

Question

Quizplus · Accepted Answer

The angle $330^\circ$ is in the fourth quadrant, where cosine values are positive. It corresponds to a reference angle of $360^\circ - 330^\circ = 30^\circ$. The cosine of $30^\circ$ is $\frac{\sqrt{3}}{2}$.

Evaluate the Cosine of the Angle Without Using a Calculator 330∘330 ^ { \circ }330∘

Evaluate the Cosine of the Angle Without Using a Calculator $330 ^ { \circ }$