Find the exact value of the expression.
-csc 840°
A) $- 2$
B) $\frac { 2 \sqrt { 3 } } { 3 }$
C) $\sqrt { 2 }$
D) $- \frac { \sqrt { 3 } } { 3 }$

Question

Find the exact value of the expression.
-csc 840° 
A) $- 2$
B) $\frac { 2 \sqrt { 3 } } { 3 }$
C) $\sqrt { 2 }$
D) $- \frac { \sqrt { 3 } } { 3 }$

Quizplus · Accepted Answer

The angle 840° is coterminal with 120° (since 840° - 720° = 120°). The cosecant of 120° is the reciprocal of the sine of 120°, which is $\frac{\sqrt{3}}{2}$. Therefore, csc 120° = $\frac{2\sqrt{3}}{3}$.

Find the Exact Value of the Expression −2- 2−2 B) 233\frac { 2 \sqrt { 3 } } { 3 }323​​

Find the Exact Value of the Expression $- 2$ B) $\frac { 2 \sqrt { 3 } } { 3 }$