Question Number 50433 by Abdo msup. last updated on 16/Dec/18
$${find}\:{all}\:{function}\:{f}\:\:{C}^{\mathrm{2}} \:{onR}\:/ \\ $$$${f}\left({x}\right)+\int_{\mathrm{0}} ^{{x}} \left({x}−{t}\right){f}\left({t}\right){dt}\:=\mathrm{1}\:\forall\:{x}\in{R}\:. \\ $$