Find the Given Power $\left[ 3 \operatorname { cis } 15 ^ { \circ } \right] ^ { 4 }$

Multiple Choice

Find the given power. Write answer in rectangular form.
- $\left[ 3 \operatorname { cis } 15 ^ { \circ } \right] ^ { 4 }$

A) $\frac { 81 } { 2 } + \frac { 81 } { 2 } \mathrm { i }$
B) $\frac { 81 } { 2 } \sqrt { 3 } + \frac { 81 } { 2 } \mathrm { i }$
C) $\frac { 81 } { 2 } + \frac { 81 } { 2 } \mathrm { i } \sqrt { 3 }$
D) $81 \mathrm { i }$