Question Number 111769 by mathmax by abdo last updated on 04/Sep/20
$$\mathrm{let}\:\mathrm{u}_{\mathrm{n}} =\sum_{\mathrm{k}=\mathrm{1}} ^{\mathrm{n}} \:\frac{\mathrm{1}}{\:\sqrt{\left(\mathrm{k}+\mathrm{n}\right)\left(\mathrm{k}+\mathrm{n}+\mathrm{1}\right)}} \\ $$$$\mathrm{detremine}\:\mathrm{lim}_{\mathrm{n}\rightarrow+\infty} \mathrm{u}_{\mathrm{n}} \\ $$