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Category: Integration

x-n-lnx-dx-

Question Number 25837 by mubeen897@hotmail.com last updated on 15/Dec/17 (xnlnx)dx Answered by kaivan.ahmadi last updated on 15/Dec/17 u=lnxdu=dxx$$\mathrm{dv}=\mathrm{x}^{\mathrm{n}} \mathrm{dx}\Rightarrow\mathrm{v}=\frac{\mathrm{x}^{\mathrm{n}+\mathrm{1}} }{\mathrm{n}+\mathrm{1}}…

answer-to-q25796-f-ind-the-value-off-x-0-pi-ln-1-xcos-d-with-0-lt-x-lt-1-f-x-0-pi-cos-1-xcos-1-d-pix-1-x-1-0-pi-1-xcos-1-d-and-by-the-changeent-tan-u-then-the

Question Number 25821 by abdo imad last updated on 15/Dec/17 $${answer}\:{to}\:{q}\mathrm{25796}\:{f}_{} {ind}\:{the}\:{value}\:{off}\left({x}\right)=\:\int_{\mathrm{0}^{} } ^{\pi_{} } {ln}\left(\mathrm{1}+{xcos}\theta\right){d}\theta\:{with}\:\mathrm{0}<{x}<\mathrm{1}\:\:\:\partial{f}/\partial{x}=\:\int_{\mathrm{0}} ^{\pi} \:\:{cos}\theta\left(\mathrm{1}+{xcos}\theta\right)^{−\mathrm{1}} {d}\theta=\pi{x}^{−\mathrm{1}} −{x}^{−\mathrm{1}} \int_{\mathrm{0}} ^{\pi} \left(\mathrm{1}+{xcos}\theta\right)^{−\mathrm{1}} {d}\theta{and}\:{by}\:{the}\:{changeent}\:{tan}\theta={u}\:{then}\:{the}\:{changement}\:{u}=\left(\left(\mathrm{1}+{x}\right)\left(\mathrm{1}+{x}\right)^{−\mathrm{1}^{} }…

Question-91326

Question Number 91326 by mhmd last updated on 29/Apr/20 Commented by mathmax by abdo last updated on 30/Apr/20 $${I}\:=\int\:\:\frac{{dx}}{\left({x}−\mathrm{1}\right)^{\mathrm{2}} \sqrt{{x}^{\mathrm{2}} −{x}+\mathrm{1}}}\:\Rightarrow\:{I}\:=_{{x}−\mathrm{1}={t}} \:\:\:\:\int\:\:\frac{{dt}}{{t}^{\mathrm{2}} \sqrt{\left({t}+\mathrm{1}\right)^{\mathrm{2}} −\left({t}+\mathrm{1}\right)+\mathrm{1}}} \