Quote:
Originally Posted by battery2004  Hello,
Ehh, i left this homework till the last day thinking it`s not too hard, but actualy i have no clue how to completely solve any of them -  
If anyone could solve just one of them it would be much appreciated!
Thanks, in advance. |
We know by Euler's Formula that
. So
![\begin{aligned}\sqrt[4]{7\left(\cos\left(\frac{\pi}{2}\right)+i\sin\left(\frac{\pi}{2}\right)\right)}&=\sqrt[4]{7}e^{\frac{\pi{i}}{8}}\\&=\sqrt[4]{7}\left(\cos\left(\frac{\pi}{8}\right)+i\sin\left(\frac{\pi}{8}\right)\right)\end{aligned}](http://www.mathhelpforum.com/math-help/latex2/img/c33001468f94219a0d693a744141c8ff-1.gif "\begin{aligned}\sqrt[4]{7\left(\cos\left(\frac{\pi}{2}\right)+i\sin\left(\frac{\pi}{2}\right)\right)}&=\sqrt[4]{7}e^{\frac{\pi{i}}{8}}\\&=\sqrt[4]{7}\left(\cos\left(\frac{\pi}{8}\right)+i\sin\left(\frac{\pi}{8}\right)\right)\end{aligned}")
Do similarly for the second.