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Category: Integration

3x-1-x-2-9-dx-

Question Number 100657 by Cheyboy last updated on 28/Jun/20 $$\int\:\:\frac{\mathrm{3}{x}−\mathrm{1}}{{x}^{\mathrm{2}} +\mathrm{9}}\:{dx} \\ $$ Commented by bobhans last updated on 28/Jun/20 $$\mathrm{set}\:\mathrm{x}\:=\:\mathrm{3tan}\:\mathrm{z}\:\Rightarrow\:\mathrm{dx}\:=\:\mathrm{3sec}\:^{\mathrm{2}} \mathrm{dz} \\ $$$$\mathrm{I}=\int\:\frac{\mathrm{2x}+\mathrm{x}−\mathrm{1}}{\mathrm{x}^{\mathrm{2}} +\mathrm{9}}\:\mathrm{dx}\:=\int\:\frac{\mathrm{d}\left(\mathrm{x}^{\mathrm{2}}…

Question-100653

Question Number 100653 by Ar Brandon last updated on 28/Jun/20 Answered by mathmax by abdo last updated on 28/Jun/20 $$\left.\mathrm{1}\left.\right)\left.\:\mathrm{f}\left(\mathrm{x}\right)\:=\frac{\mathrm{sin}\left(\mathrm{nx}\right)}{\mathrm{sinx}}\:\mathrm{is}\:\mathrm{continue}\:\:\mathrm{on}\right]\mathrm{0},\frac{\pi}{\mathrm{2}}\right]\:\Rightarrow\:\mathrm{integrable}\:\mathrm{at}\:\mathrm{V}\left(\mathrm{0}\right)\:\mathrm{we}\:\mathrm{have} \\ $$$$\mathrm{f}\left(\mathrm{x}\right)\sim\frac{\mathrm{nx}}{\mathrm{x}}\:=\mathrm{n}\:\mathrm{so}\:\:\mathrm{I}_{\mathrm{n}} \mathrm{exist} \\ $$$$\left.\mathrm{2}\right)\mathrm{I}_{\mathrm{n}}…

2x-3-x-4-3x-2-dx-

Question Number 35117 by math1967 last updated on 15/May/18 $$\int\frac{\mathrm{2}{x}+\mathrm{3}}{{x}^{\mathrm{4}} −\mathrm{3}{x}−\mathrm{2}}{dx} \\ $$ Answered by MJS last updated on 16/May/18 $$\int\frac{\mathrm{2}{x}+\mathrm{3}}{{x}^{\mathrm{4}} −\mathrm{3}{x}−\mathrm{2}}{dx}=\int\frac{\mathrm{2}{x}+\mathrm{3}}{\left({x}^{\mathrm{2}} −{x}−\mathrm{1}\right)\left({x}^{\mathrm{2}} +{x}+\mathrm{2}\right)}{dx}= \\…

prove-that-0-1-ln-2-1-x-x-2-dx-2-2-proof-1-x-ln-2-1-x-0-1-0-1-2ln-1-x-x-1-x-dx-lim-1-1-l

Question Number 166180 by mnjuly1970 last updated on 15/Feb/22 $$ \\ $$$$\:\:\:\:\:\:{prove}\:\:{that} \\ $$$$\:\:\:\:\:\boldsymbol{\phi}=\int_{\mathrm{0}} ^{\:\mathrm{1}} \frac{\:{ln}^{\:\mathrm{2}} \left(\mathrm{1}−{x}\:\right)}{{x}^{\:\mathrm{2}} }\:{dx}\:=\:\mathrm{2}\:\zeta\:\left(\mathrm{2}\right) \\ $$$$\:\:\:\:\:\:−−−{proof}−−− \\ $$$$\:\:\:\:\boldsymbol{\phi}=\:\left[\frac{−\mathrm{1}}{{x}}\:{ln}^{\:\mathrm{2}} \left(\mathrm{1}−{x}\right)\:\right]_{\mathrm{0}} ^{\mathrm{1}} −\int_{\mathrm{0}}…