Question : Determine the sq root of $\displaystyle (3+4i) , \ \ i=\sqrt{-1}$
3+4i=5(cos(38.86...+2pi*k)* + isin(36.86...+2pi*k)*)=5cis(36.86... +2pi*k)*
square root of above can be calculate with de Moivre formula.
De Moivre's formula - Wikipedia, the free encyclopedia