Answer
$\dfrac{27}{2}+\dfrac{27\sqrt {3}}{2}i$
Work Step by Step
Applying De Moivre's theorem, we have
\begin{align*}
[\sqrt {3}(\cos 10^{\circ}+i\sin 10^{\circ})]^{6}&=(\sqrt {3})^{6}[\cos(6\cdot10^{\circ})+i\sin(6\cdot10^{\circ})]\\
&=27(\cos 60^{\circ}+i\sin 60^{\circ})\\
&=27\left(\frac{1}{2}+\frac{\sqrt {3}}{2}i\right)\\
&= \frac{27}{2}+\frac{27\sqrt {3}}{2}i\end{align*}