Find the Slope of the Polar Curve at the Indicated $$r = 6 \cos 3 \theta , \theta = \frac { \pi } { 3 }$$

Multiple Choice

Find the slope of the polar curve at the indicated point.
- $$r = 6 \cos 3 \theta , \theta = \frac { \pi } { 3 }$$

A) $- \frac { \sqrt { 3 } } { 3 }$
B) $- \sqrt { 3 }$
C) $\sqrt { 3 }$
D) $\frac { \sqrt { 3 } } { 3 }$