Question Number 50360 by prof Abdo imad last updated on 16/Dec/18
$${find}\:{radius}\:{of}\:{convergence}\:{for}\:{the}\:{serie} \\ $$$$\sum_{{n}=\mathrm{0}} ^{\infty} \left\{\left(\mathrm{1}+{i}\right)^{{n}} −\left(\mathrm{1}−{i}\right)^{{n}} \right\}{x}^{{n}} \\ $$