Question Number 92767 by mathmax by abdo last updated on 09/May/20
$${let}\:{U}_{{n}} =\int_{\mathrm{0}} ^{\mathrm{1}} \:{e}^{−{nx}} {cosx}\:{dx} \\ $$$$\left.\mathrm{1}\right)\:{determine}\:{lim}_{{n}\rightarrow+\infty} {n}^{\mathrm{2}} \:{U}_{{n}} \\ $$$$\left.\mathrm{2}\right){calculate}\:\sum_{{n}=\mathrm{0}} ^{\infty} \:{U}_{{n}} \\ $$