Question Number 34593 by abdo mathsup 649 cc last updated on 08/May/18
$$\left.\mathrm{1}\right)\:{calculate}\:\:\int_{−\infty} ^{+\infty} \:\:\:\frac{{cos}\left(\alpha{x}^{{n}} \right)}{{x}^{\mathrm{2}} \:+{x}\:+\mathrm{1}}\:{dx}\:\:{with}\:{n}\:{integr} \\ $$$${natural} \\ $$$$\left.\mathrm{2}\right)\:{find}\:{the}\:{value}\:{of}\:\:\:\int_{−\infty} ^{\infty} \:\:\:\:\frac{{cos}\left(\:\alpha\:{x}^{\mathrm{2}{n}} \right)}{{x}^{\mathrm{2}} \:+{x}\:+\mathrm{1}}{dx} \\ $$$$\left.\mathrm{3}\right)\:{calculate}\:\:\int_{−\infty} ^{+\infty} \:\:\:\:\frac{{cos}\left(\pi\:{x}^{\mathrm{3}} \right)}{{x}^{\mathrm{2}} \:+{x}\:+\mathrm{1}}\:{dx} \\ $$