Find the Derivative of the Function $s ( x ) = 2 \cos ^ { 2 } x$

Multiple Choice

Find the derivative of the function. $s ( x ) = 2 \cos ^ { 2 } x$

A) $s '( x ) = - 4 \cos ( x ) \cdot \cos x$
B) $s '( x ) = - 4 \cos ( x ) \cdot \sin x$
C) $s ^ { \prime } ( x ) = - 2 \cos ^ { 2 } ( x ) \cdot \sin x$
D) $s' ( x ) = - 2 \cos ( x ) \cdot \sin x$
E) $s' ( x ) = - 4 \csc x$