Find the exact value of the given expression. $\cos \left( 120 ^ { \circ } + 315 ^ { \circ } \right)$
A) $\frac { ( 1 - \sqrt { 3 } ) ( 2 \sqrt { 2 } ) } { 8 }$
B) $\frac { ( - 1 + \sqrt { 3 } ) ( 2 \sqrt { 2 } ) } { 8 }$
C) $\frac { ( 1 + \sqrt { 3 } ) ( 2 \sqrt { 2 } ) } { 8 }$
D) $\frac { ( - 1 - \sqrt { 3 } ) ( 2 \sqrt { 2 } ) } { 8 }$

Question

Quizplus · Accepted Answer

The Answer of Find the exact value of the given expression. $\cos \left( 120 ^ { \circ } + 315 ^ { \circ } \right)$
A) $\frac { ( 1 - \sqrt { 3 } ) ( 2 \sqrt { 2 } ) } { 8 }$
B) $\frac { ( - 1 + \sqrt { 3 } ) ( 2 \sqrt { 2 } ) } { 8 }$
C) $\frac { ( 1 + \sqrt { 3 } ) ( 2 \sqrt { 2 } ) } { 8 }$
D) $\frac { ( - 1 - \sqrt { 3 } ) ( 2 \sqrt { 2 } ) } { 8 }$

Find the Exact Value of the Given Expression cos⁡(120∘+315∘)\cos \left( 120 ^ { \circ } + 315 ^ { \circ } \right)cos(120∘+315∘)

Find the Exact Value of the Given Expression $\cos \left( 120 ^ { \circ } + 315 ^ { \circ } \right)$