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Category: Integration

1-x-3-3x-7-dx-

Question Number 197191 by tri26112004 last updated on 10/Sep/23 $$\int\frac{\mathrm{1}}{{x}^{\mathrm{3}} −\mathrm{3}{x}+\mathrm{7}}{dx} \\ $$ Answered by Frix last updated on 10/Sep/23 $${x}^{\mathrm{3}} −\mathrm{3}{x}+\mathrm{7}=\left({x}−{a}\right)\left({x}^{\mathrm{2}} +{ax}+{b}\right) \\ $$$${a}=−\frac{\sqrt[{\mathrm{3}}]{\mathrm{7}+\mathrm{3}\sqrt{\mathrm{5}}}+\sqrt[{\mathrm{3}}]{\mathrm{7}−\mathrm{3}\sqrt{\mathrm{5}}}}{\:\sqrt[{\mathrm{3}}]{\mathrm{2}}};\:{b}=−\frac{\mathrm{7}}{{a}}…

Prove-that-pi-2-0-ln-1-sint-sint-dt-pi-2-8-1-2-arccos-2-

Question Number 197060 by universe last updated on 07/Sep/23 $$\mathrm{Prove}\:\mathrm{that}\: \\ $$$$\underset{\:\mathrm{0}} {\int}^{\:\frac{\pi}{\mathrm{2}}} \frac{\mathrm{ln}\left(\mathrm{1}+\alpha\mathrm{sin}{t}\right)}{\mathrm{sin}{t}}{dt}=\:\frac{\pi^{\mathrm{2}} }{\mathrm{8}}−\frac{\mathrm{1}}{\mathrm{2}}\left(\mathrm{arccos}\alpha\right)^{\mathrm{2}} \\ $$ Commented by universe last updated on 07/Sep/23 $${question}\:\mathrm{196950}…

Question-196983

Question Number 196983 by universe last updated on 05/Sep/23 Commented by Frix last updated on 06/Sep/23 $$\mathrm{I}\:\mathrm{can}'\mathrm{t}\:\mathrm{solve}\:\mathrm{the}\:\mathrm{first}\:\mathrm{2}\:\mathrm{but}\:\mathrm{wolframalpha}\:\mathrm{can} \\ $$$$\left(\mathrm{C}\:\mathrm{is}\:\mathrm{the}\:\mathrm{Catalan}\:\mathrm{constant}\right) \\ $$$$\mathrm{1}.\:{I}_{\mathrm{1}} =\underset{\mathrm{0}} {\overset{\pi} {\int}}\frac{{x}^{\mathrm{3}} }{…}{dx}=\frac{\pi\left(−\mathrm{1440C}+\mathrm{1144}+\mathrm{15}\pi\left(−\mathrm{41}+\mathrm{20}\pi+\mathrm{24ln}\:\mathrm{2}\right)\right)}{\mathrm{3780}}…

xe-1-2x-dx-

Question Number 196832 by Frix last updated on 01/Sep/23 $$\int{x}\mathrm{e}^{\frac{\mathrm{1}}{\mathrm{2}{x}}} {dx}=? \\ $$ Commented by mokys last updated on 02/Sep/23 $${u}\:=\:\frac{\mathrm{1}}{\mathrm{2}{x}}\:\rightarrow\:{x}\:=\:\frac{\mathrm{1}}{\mathrm{2}{u}}\:\rightarrow\:{dx}\:=\:−\:\frac{{du}}{\mathrm{2}{u}^{\mathrm{2}} } \\ $$$$ \\…