Is there a formula to find the square root of a complex number? I can't find it anywhere... Thanks.
See...
de Moivre's formula - Wikipedia, the free encyclopedia
... 'Applications'... a complex number $\displaystyle z \ne 0$ has two distinct square roots...
Kind regards
$\displaystyle \chi$ $\displaystyle \sigma$
The easiest way is to convert the complex number to exponential form, because
$\displaystyle \left(r\,e^{i\theta}\right)^{\frac{1}{2}} = r^{\frac{1}{2}}e^{\frac{1}{2}i\theta}$.
Note that this only gives you one of the square roots, but you can use the fact that the roots will be evenly placed around a circle to find the other.