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Question-19452

Question Number 19452 by icyfalcon999 last updated on 11/Aug/17 Answered by Tinkutara last updated on 11/Aug/17 $$\int\frac{{dx}}{{x}^{\mathrm{2}} \:+\:\mathrm{1}}\:=\:\mathrm{tan}^{−\mathrm{1}} {x} \\ $$$$\left[\mathrm{tan}^{−\mathrm{1}} {x}\right]_{−\infty} ^{\infty} \:=\:\frac{\pi}{\mathrm{2}}\:−\:\left(−\frac{\pi}{\mathrm{2}}\right)\:=\:\pi \\…

x-x-3-x-9-8-1-3-2x-x-3-3x-1-3-

Question Number 150527 by Jamshidbek last updated on 13/Aug/21 $$\sqrt[{\mathrm{3}}]{\mathrm{x}\left(\mathrm{x}−\mathrm{3}\right)\left(\mathrm{x}−\mathrm{9}\right)−\mathrm{8}}=\mathrm{2x}+\sqrt[{\mathrm{3}}]{\mathrm{x}^{\mathrm{3}} −\mathrm{3x}} \\ $$ Answered by MJS_new last updated on 13/Aug/21 $$\mathrm{trying}\:\mathrm{something}\:\mathrm{weird}: \\ $$$$\mathrm{assuming}\:\sqrt[{\mathrm{3}}]{{x}^{\mathrm{3}} −\mathrm{3}{x}}={y}\in\mathbb{R} \\…

Find-all-solutions-of-x-y-such-that-x-3-3xy-2-2010-y-3-3x-2-y-2009-x-y-R-

Question Number 84909 by naka3546 last updated on 17/Mar/20 $${Find}\:\:\:{all}\:\:{solutions}\:\:{of}\:\:\left({x},\:{y}\right)\:\:{such}\:\:{that} \\ $$$$\:\:\:\:\:\:\:\:{x}^{\mathrm{3}} \:−\:\mathrm{3}{xy}^{\mathrm{2}} \:\:=\:\:\mathrm{2010} \\ $$$$\:\:\:\:\:\:\:\:{y}^{\mathrm{3}} \:−\:\mathrm{3}{x}^{\mathrm{2}} {y}\:\:=\:\:\mathrm{2009} \\ $$$${x},\:{y}\:\:\in\:\:\mathbb{R} \\ $$ Commented by john…

n-0-2n-1-8-n-n-2-Help-please-

Question Number 150432 by Jamshidbek last updated on 12/Aug/21 $$\underset{\mathrm{n}=\mathrm{0}} {\overset{\infty} {\sum}}\frac{\left(\mathrm{2n}+\mathrm{1}\right)!}{\mathrm{8}^{\mathrm{n}} \centerdot\left(\mathrm{n}!\right)^{\mathrm{2}} }=?\:\:\:\:\:\mathrm{Help}\:\mathrm{please} \\ $$ Answered by Olaf_Thorendsen last updated on 12/Aug/21 $${f}\left({x}\right)\:=\:\frac{\mathrm{1}}{\:\left(\mathrm{1}−{x}\right)^{\mathrm{3}/\mathrm{2}} }\:=\:\left(\mathrm{1}−{x}\right)^{−\frac{\mathrm{3}}{\mathrm{2}}}…

Find-the-equations-of-the-common-tangents-to-the-parabola-y-2-4x-and-the-parabola-x-2-2y-3-

Question Number 150429 by ZiYangLee last updated on 12/Aug/21 $$\mathrm{Find}\:\mathrm{the}\:\mathrm{equations}\:\mathrm{of}\:\mathrm{the}\:\mathrm{common} \\ $$$$\mathrm{tangents}\:\mathrm{to}\:\mathrm{the}\:\mathrm{parabola}\:{y}^{\mathrm{2}} =\mathrm{4}{x}\:\mathrm{and} \\ $$$$\mathrm{the}\:\mathrm{parabola}\:{x}^{\mathrm{2}} =\mathrm{2}{y}−\mathrm{3}. \\ $$ Answered by Olaf_Thorendsen last updated on 12/Aug/21…

Question-84884

Question Number 84884 by bshahid010@gmail.com last updated on 17/Mar/20 Commented by mathmax by abdo last updated on 17/Mar/20 $${A}\:=\int\:\:\frac{{dx}}{\left(\mathrm{2}{x}−\mathrm{1}\right)\sqrt{{x}^{\mathrm{2}} +{x}+\mathrm{3}}}\:{changement}\:\mathrm{2}{x}−\mathrm{1}={t}\:{give}\:{x}=\frac{{t}+\mathrm{1}}{\mathrm{2}} \\ $$$${A}\:=\int\:\:\frac{{dt}}{\mathrm{2}{t}\sqrt{\frac{\left({t}+\mathrm{1}\right)^{\mathrm{2}} }{\mathrm{4}}+\frac{{t}+\mathrm{1}}{\mathrm{2}}+\mathrm{3}}}\:=\int\:\:\frac{{dt}}{\mathrm{2}{t}\sqrt{\frac{{t}^{\mathrm{2}} +\mathrm{2}{t}+\mathrm{1}+\mathrm{2}{t}+\mathrm{2}+\mathrm{12}}{\mathrm{4}}}} \\…