Find the Average Value of the Function $f ( x )$

Multiple Choice

Find the average value of the function $f ( x )$ in the interval $[ - \pi , \pi ]$ .
$$f ( x ) = \sin ^ { 6 } x \cos ^ { 5 } x$$

A) $\pi$
B) 0
C) $\frac { \pi } { 5 }$
D) $\frac { \pi } { 12 }$
E) $\frac { \pi } { 6 }$