Question Number 35611 by abdo mathsup 649 cc last updated on 21/May/18
$${let}\:{h}\left({t}\right)\:=\:{e}^{{t}−{e}^{{t}} } \:\:\:\:{and}\:{for}\:{n}\geqslant\mathrm{0}\:{we}\:{put} \\ $$$${h}_{{n}} \left({t}\right)\:={nh}\left({nt}\right) \\ $$$${calculate}\:\:\int_{−\infty} ^{+\infty} \:{h}_{{n}} \left({t}\right){dt}\:. \\ $$