Find the Exact Value of S in the Given Interval $$\left[ \frac { \pi } { 2 } , \pi \right] ; \cos \mathrm { s } = - \frac { \sqrt { 3 } } { 2 }$$

Multiple Choice

Find the exact value of s in the given interval that has the given circular function value.
- $$\left[ \frac { \pi } { 2 } , \pi \right] ; \cos \mathrm { s } = - \frac { \sqrt { 3 } } { 2 }$$

A) $s = \frac { \pi } { 6 }$
B) $s = \frac { 2 \pi } { 3 }$
C) $s = \frac { 3 \pi } { 4 }$
D) $\mathrm { s } =$