In the Previous Four Problems, the Infinite Series Solution of the Original

Multiple Choice

In the previous four problems, the infinite series solution of the original problem is $u = \sum _ { n = 1 } ^ { \infty } r ^ { n } \left( A _ { n } \cos ( n \theta ) + B _ { n } \sin ( n \theta ) \right)$ where Select all that apply.

A) $A _ { n } = \int _ { 0 } ^ { 2 \pi } f ( \theta ) \cos ( n \theta ) d \theta / \left( c ^ { n } \pi \right)$
B) $B _ { n } = \int _ { 0 } ^ { 2 \pi } f ( \theta ) \sin ( n \theta ) d \theta / \left( c ^ { n } \pi \right)$
C) $B _ { n } = \int _ { 0 } ^ { 2 \pi } f ( \theta ) \cos ( n \theta ) d \theta / \left( c ^ { n } \pi \right)$
D) $A _ { n } = 0$
E) $B _ { n } = 0$