Question Number 44468 by maxmathsup by imad last updated on 29/Sep/18
$${let}\:{u}_{{n}} =\:\sum_{{k}=\mathrm{1}} ^{{n}} \:\:\frac{{e}^{−{k}} }{\:\sqrt{{k}}} \\ $$$${find}\:{a}\:{equivalent}\:{of}\:{u}_{{n}} \:{when}\:{n}\rightarrow+\infty\:. \\ $$