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Category: Integration

dx-x-x-x-

Question Number 116701 by bemath last updated on 06/Oct/20 $$\int\:\frac{\mathrm{dx}}{\mathrm{x}+\mathrm{x}\sqrt{\mathrm{x}}}\:=? \\ $$ Commented by bobhans last updated on 06/Oct/20 $$\:\int\:\frac{\mathrm{dx}}{\mathrm{x}+\mathrm{x}\sqrt{\mathrm{x}}\:}\:=\:\int\:\frac{\mathrm{dx}}{\mathrm{x}\left(\mathrm{1}+\sqrt{\mathrm{x}}\:\right)} \\ $$$$\left[\:\mathrm{letting}\:\mathrm{x}\:=\:\lambda^{\mathrm{2}} \:\rightarrow\mathrm{dx}\:=\:\mathrm{2}\lambda\:\mathrm{d}\lambda\:\right]\: \\ $$$$\mathrm{I}=\int\:\frac{\mathrm{2}\lambda\:\mathrm{d}\lambda}{\lambda^{\mathrm{2}}…

Help-please-to-solve-this-If-f-x-1-x-2-for-x-2-2-and-f-x-5-otherwise-Then-what-is-the-value-of-2-2-f-2x-2-dx-

Question Number 116687 by megrex last updated on 05/Oct/20 $${Help}\:{please},\:{to}\:{solve}\:{this}\:… \\ $$$${If}\:{f}\left({x}\right)=\mathrm{1}+{x}^{\mathrm{2}} \:\:{for}\:{x}\in\left[−\mathrm{2},\mathrm{2}\right]\:{and}\: \\ $$$$\:\:\:\:\:\:{f}\left({x}\right)=\mathrm{5}\:\:\:\:\:\:\:\:{otherwise}. \\ $$$${Then}\:{what}\:{is}\:{the}\:{value}\:{of} \\ $$$$\int_{−\mathrm{2}} ^{+\mathrm{2}} {f}\left(\mathrm{2}{x}^{\mathrm{2}} \right){dx}? \\ $$$$ \\…

nice-calculus-prove-that-I-0-1-pi-4-Arctan-x-dx-1-x-2-G-2-G-is-catalan-constant-M-N-1970

Question Number 116672 by mnjuly1970 last updated on 05/Oct/20 $$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:…\:\:\:{nice}\:\:{calculus}\:… \\ $$$$ \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:{prove}\:\:{that}\:: \\ $$$$ \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\mathrm{I}\:=\:\int_{\mathrm{0}} ^{\:\mathrm{1}} \left(\frac{\pi}{\mathrm{4}}\:\:−\mathscr{A}{rctan}\left({x}\right)\right)\frac{{dx}}{\mathrm{1}−{x}^{\mathrm{2}} }\:=\:\frac{\mathrm{G}}{\mathrm{2}}\:\:\checkmark\:\:\:\: \\ $$$$\:\:\:\:\:\:\: \\ $$$$\mathrm{G}\:{is}\:\:\:{catalan}\:\:{constant}\:……

nice-calculus-very-nice-integral-demonstrate-0-1-1-x-1-x-x-2-x-3-log-x-dx-log-1-2-m-n-1970-

Question Number 116667 by mnjuly1970 last updated on 05/Oct/20 $$\:\:\:\:\:\:\:\:\:\:\:\:…\:\:\:{nice}\:\:{calculus}… \\ $$$$ \\ $$$$\:\:\:\:\:\:{very}\:{nice}\:\:{integral}:: \\ $$$$\:\:\:\:\:\:\:{demonstrate}::: \\ $$$$ \\ $$$$\:\:\:\:\:\:\:\:\Omega\:=\:\int_{\mathrm{0}} ^{\:\mathrm{1}} \frac{\mathrm{1}−{x}}{\left(\mathrm{1}+{x}+{x}^{\mathrm{2}} +{x}^{\mathrm{3}} \right){log}\left({x}\right)}\:{dx}\overset{???} {=}{log}\left(\sqrt{\frac{\mathrm{1}}{\mathrm{2}}}\right)…

dx-tgx-tgx-

Question Number 51122 by behi83417@gmail.com last updated on 24/Dec/18 $$\int\:\:\:\:\frac{\boldsymbol{\mathrm{dx}}}{\boldsymbol{\mathrm{tgx}}−\sqrt{\boldsymbol{\mathrm{tgx}}}}=? \\ $$ Commented by MJS last updated on 24/Dec/18 $$\mathrm{long}\:\mathrm{way}… \\ $$$$\mathrm{start}\:\mathrm{with} \\ $$$${t}=\sqrt{\mathrm{tan}\:{x}}\:\rightarrow\:{dx}=\frac{\mathrm{2}{t}}{{t}^{\mathrm{4}} +\mathrm{1}}{dt}…