\[1)\ \sqrt{3}\left( \cos\frac{\pi}{6} + i\sin\frac{\pi}{6} \right) =\]
\[= \sqrt{3}\left( \frac{\sqrt{3}}{2} + \frac{1}{2}i \right) = \frac{3}{2} + \frac{\sqrt{3}}{2}i;\]
\[2)\ 4\left( \cos\frac{5\pi}{4} + i\sin\frac{5\pi}{4} \right) =\]
\[= 4\left( - \frac{\sqrt{2}}{2} - \frac{\sqrt{2}}{2}i \right) =\]
\[= - 2\sqrt{2} - 2\sqrt{2}i.\]