Find Dy
- $$y = \cos ( 3 \sqrt { x } )$$

Multiple Choice

Find dy.
- $$y = \cos ( 3 \sqrt { x } )$$

A) $\left( \frac { 3 \sin ( 3 \sqrt { x } ) } { 2 \sqrt { x } } \right) d x$
B) $\left( \frac { - 3 \sqrt { x } \sin ( 3 \sqrt { x } ) } { 2 } \right) d x$
C) $\left( \frac { 3 \sqrt { x } \sin ( 3 \sqrt { x } ) } { 2 } \right) d x$
D) $\left( \frac { - 3 \sin ( 3 \sqrt { x } ) } { 2 \sqrt { x } } \right) d x$