Question Number 85648 by sakeefhasan05@gmail.com last updated on 23/Mar/20
$$\int\frac{\left(\mathrm{x}^{\mathrm{3}} −\mathrm{4}\right)}{\left(\mathrm{x}+\mathrm{1}\right)}\mathrm{dx} \\ $$
Answered by petrochengula last updated on 23/Mar/20
$$=\int\frac{{x}^{\mathrm{3}} +\mathrm{1}−\mathrm{5}}{\left({x}+\mathrm{1}\right)}{dx} \\ $$$$=\int\frac{{x}^{\mathrm{3}} +\mathrm{1}}{{x}+\mathrm{1}}{dx}−\mathrm{5}\int\frac{\mathrm{1}}{{x}+\mathrm{1}}{dx} \\ $$$$=\int\frac{\left({x}+\mathrm{1}\right)\left({x}^{\mathrm{2}} −{x}+\mathrm{1}\right)}{{x}+\mathrm{1}}{dx}−\mathrm{5}{ln}\mid{x}+\mathrm{1}\mid+{C} \\ $$$$=\frac{{x}^{\mathrm{3}} }{\mathrm{3}}−\frac{{x}^{\mathrm{2}} }{\mathrm{2}}+{x}−\mathrm{5}{ln}\mid{x}+\mathrm{1}\mid+{C} \\ $$$$ \\ $$
Answered by petrochengula last updated on 23/Mar/20
$$=\int\frac{{x}^{\mathrm{3}} +\mathrm{1}−\mathrm{5}}{\left({x}+\mathrm{1}\right)}{dx} \\ $$$$=\int\frac{{x}^{\mathrm{3}} +\mathrm{1}}{{x}+\mathrm{1}}{dx}−\mathrm{5}\int\frac{\mathrm{1}}{{x}+\mathrm{1}}{dx} \\ $$$$=\int\frac{\left({x}+\mathrm{1}\right)\left({x}^{\mathrm{2}} −{x}+\mathrm{1}\right)}{{x}+\mathrm{1}}{dx}−\mathrm{5}{ln}\mid{x}+\mathrm{1}\mid+{C} \\ $$$$=\frac{{x}^{\mathrm{3}} }{\mathrm{3}}−\frac{{x}^{\mathrm{2}} }{\mathrm{2}}+{x}−\mathrm{5}{ln}\mid{x}+\mathrm{1}\mid+{C} \\ $$$$ \\ $$