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Category: Integration

let-I-dx-x-i-n-and-J-dx-x-i-n-1-calculate-I-and-J-interms-of-n-2-find-thevalue-of-integral-A-n-cos-narctan-1-x-1-x-2-n-

Question Number 61885 by maxmathsup by imad last updated on 10/Jun/19 $${let}\:{I}\:=\int_{−\infty} ^{+\infty} \:\:\frac{{dx}}{\left({x}+{i}\right)^{{n}} }\:\:{and}\:{J}\:=\int_{−\infty} ^{+\infty} \:\:\frac{{dx}}{\left({x}−{i}\right)^{{n}} } \\ $$$$\left.\mathrm{1}\right)\:{calculate}\:{I}\:{and}\:{J}\:{interms}\:{of}\:{n} \\ $$$$\left.\mathrm{2}\right)\:{find}\:{thevalue}\:{of}\:{integral} \\ $$$${A}_{{n}} \:\:=\int_{−\infty}…

let-f-n-a-cos-nx-x-2-x-a-2-dx-with-a-1-1-find-a-explicit-form-of-f-n-a-2-study-the-convervenge-of-f-n-a-3-determine-also-g-n-a-cos-nx

Question Number 61884 by maxmathsup by imad last updated on 10/Jun/19 $${let}\:{f}_{{n}} \left({a}\right)\:=\int_{−\infty} ^{+\infty} \:\:\:\frac{{cos}\left({nx}\right)}{\left({x}^{\mathrm{2}} +{x}\:\:+{a}\right)^{\mathrm{2}} }{dx}\:\:\:\:{with}\:\:\:{a}\geqslant\mathrm{1} \\ $$$$\left.\mathrm{1}\right)\:{find}\:{a}\:{explicit}\:{form}\:{of}\:{f}_{{n}} \left({a}\right) \\ $$$$\left.\mathrm{2}\right){study}\:{the}\:{convervenge}\:{of}\:\Sigma\:{f}_{{n}} \left({a}\right) \\ $$$$\left.\mathrm{3}\right)\:{determine}\:{also}\:{g}_{{n}}…

xln-x-x-ln-3-x-dx-

Question Number 61874 by aliesam last updated on 10/Jun/19 $$\int\frac{{xln}\left({x}\right)−{x}}{{ln}^{\mathrm{3}} \left({x}\right)}\:{dx} \\ $$ Commented by Prithwish sen last updated on 10/Jun/19 $$\int\left[\frac{\mathrm{x}}{\left[\mathrm{ln}\left(\mathrm{x}\right)\right]^{\mathrm{2}} }\:−\frac{\mathrm{x}}{\left[\mathrm{ln}\left(\mathrm{x}\right)\right]^{\mathrm{3}} }\:\right]\mathrm{dx} \\…

Question-192933

Question Number 192933 by mnjuly1970 last updated on 31/May/23 Answered by MM42 last updated on 01/Jun/23 $${ln}\left(\mathrm{1}−{x}\right)={u}\Rightarrow\frac{−\mathrm{1}}{\mathrm{1}−{x}}{dx}={du}\:\:\&{i}\:{x}^{{n}−\mathrm{1}} {dx}={dv}\Rightarrow\frac{{x}^{{n}} }{{n}}={v} \\ $$$$\Rightarrow{I}_{{n}} =\int{x}^{{n}−\mathrm{1}} {ln}\left(\mathrm{1}−{x}\right){dx}=\frac{{x}^{{n}} {ln}\left(\mathrm{1}−{x}\right)}{{n}}\:+\frac{\mathrm{1}}{{n}}\int\:\frac{{x}^{{n}} }{\mathrm{1}−{x}}{dx}…

Question-192916

Question Number 192916 by Mingma last updated on 31/May/23 Answered by ARUNG_Brandon_MBU last updated on 31/May/23 $${I}=\int_{\mathrm{0}} ^{\frac{\pi}{\mathrm{2}}} \left(\frac{\mathrm{1}−\mathrm{sin2}{x}}{\mathrm{1}+\mathrm{cos}{x}}+\frac{\mathrm{1}−\mathrm{cos2}{x}}{\mathrm{1}+\mathrm{sin}{x}}\right){dx} \\ $$$$\:\:\:=\int_{\mathrm{0}} ^{\frac{\pi}{\mathrm{2}}} \frac{{dx}}{\mathrm{1}+\mathrm{cos}{x}}+\mathrm{2}\int_{\mathrm{0}} ^{\frac{\pi}{\mathrm{2}}} \frac{\mathrm{cos}{x}}{\mathrm{1}+\mathrm{cos}{x}}\left(\mathrm{sin}{xdx}\right)+\mathrm{2}\int_{\mathrm{0}}…