Set Up an Integral for the Length of the Curve $$y = 6 \cos x , 0 \leq x \leq \pi$$

Multiple Choice

Set up an integral for the length of the curve.
- $$y = 6 \cos x , 0 \leq x \leq \pi$$

A) $\int _ { 0 } ^ { \pi } \sqrt { 1 + 6 \sin x } d x$
B) $\int _ { 0 } ^ { \pi } \sqrt { 1 - 6 \sin x } d x$
C) $\int _ { 0 } ^ { \pi } \sqrt { 1 + 36 \cos ^ { 2 } x } d x$
D) $\int _ { 0 } ^ { \pi } \sqrt { 1 + 36 \sin ^ { 2 } x } d x$