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Category: Algebra

1-find-P-R-x-P-sinx-sin-2n-1-x-2-find-the-roots-of-P-and-degP-3-decompose-1-P-and-prove-that-2n-1-sin-2n-1-x-k-0-2n-1-k-cos-kpi-2n-1-sinx-sin-kpi-2n-1

Question Number 28265 by abdo imad last updated on 22/Jan/18 $$\left.\mathrm{1}\right)\:\:{find}\:{P}\in{R}\left[{x}\right]\:/\:{P}\left({sinx}\right)\:={sin}\left(\mathrm{2}{n}+\mathrm{1}\right){x} \\ $$$$\left.\mathrm{2}\right)\:{find}\:{the}\:{roots}\:{of}\:{P}\:{and}\:{degP} \\ $$$$\left.\mathrm{3}\right)\:{decompose}\:\:\frac{\mathrm{1}}{{P}}\:\:{and}\:{prove}\:{that} \\ $$$$\frac{\mathrm{2}{n}+\mathrm{1}}{{sin}\left(\mathrm{2}{n}+\mathrm{1}\right){x}}\:=\:\sum_{{k}=\mathrm{0}} ^{\mathrm{2}{n}} \:\:\:\:\frac{\left(−\mathrm{1}\right)^{{k}} \:{cos}\left(\frac{{k}\pi}{\mathrm{2}{n}+\mathrm{1}}\right)}{{sinx}−{sin}\:\left(\frac{{k}\pi}{\left.\mathrm{2}{n}+\mathrm{1}\right)}\right)}\:\:. \\ $$ Terms of Service…

Question-159332

Question Number 159332 by 0731619 last updated on 15/Nov/21 Commented by bobhans last updated on 16/Nov/21 $$\left(\mathrm{1}\right)\mathrm{lim}_{\mathrm{x}\rightarrow\mathrm{1}^{−} } \:\sqrt{\mathrm{x}−\mathrm{1}}\:=\:\mathrm{undefined}\: \\ $$$$\:\:\:\:\:\:\mathrm{lim}_{\mathrm{x}\rightarrow\mathrm{1}^{+} } \:\sqrt{\mathrm{x}−\mathrm{1}}\:=\:\mathrm{0} \\ $$$$\left(\mathrm{2}\right)\:\mathrm{lim}_{\mathrm{x}\rightarrow\mathrm{1}^{−}…

Question-159300

Question Number 159300 by saly last updated on 15/Nov/21 Answered by Derrick last updated on 15/Nov/21 $${preve} \\ $$$$\left.{a}\right){montrons}\:{par}\:{double}\:{inclusion} \\ $$$${soit}\:{x} \\ $$$${x}\in{f}^{−\mathrm{1}} \:\left({A}\cup{B}\right)\Leftrightarrow{f}\left({x}\right)\in\left({A}\cup{B}\right) \\…

Question-28219

Question Number 28219 by math solver last updated on 22/Jan/18 Commented by mrW2 last updated on 22/Jan/18 $${z}={x}+{iy} \\ $$$$\left(\mathrm{2}{x}−\mathrm{1}\right)^{\mathrm{2}} +\left(\mathrm{2}{y}\right)^{\mathrm{2}} =\left({x}−\mathrm{1}\right)^{\mathrm{2}} +{y}^{\mathrm{2}} \\ $$$${x}^{\mathrm{2}}…

Find-0-x-arctan-x-x-1-x-2-1-dx-

Question Number 159292 by HongKing last updated on 15/Nov/21 $$\mathrm{Find}:\:\:\boldsymbol{\Omega}\:=\underset{\:\mathrm{0}} {\overset{\:\infty} {\int}}\frac{\mathrm{x}\:\mathrm{arctan}\left(\mathrm{x}\right)}{\left(\mathrm{x}\:+\:\mathrm{1}\right)\left(\mathrm{x}^{\mathrm{2}} \:+\:\mathrm{1}\right)}\:\mathrm{dx} \\ $$$$ \\ $$ Answered by mindispower last updated on 15/Nov/21 $$=\int_{\mathrm{0}}…

Question-159281

Question Number 159281 by HongKing last updated on 14/Nov/21 Commented by MJS_new last updated on 14/Nov/21 $${x}=−\frac{\mathrm{1}}{\mathrm{3}} \\ $$$$\mathrm{how}? \\ $$$$\mathrm{obviously}\:{x}<\mathrm{0}\:\mathrm{because}\:\mathrm{otherwise}\:\mathrm{lhs}\:>\mathrm{0} \\ $$$$\mathrm{but}\:\mathrm{with}\:{x}=−\mathrm{1}\:\mathrm{lhs}\:<\mathrm{0}\:\Rightarrow\:−\mathrm{1}<{x}<\mathrm{0} \\ $$$$\mathrm{then}\:\mathrm{I}\:\mathrm{tried}\:{x}=−\frac{\mathrm{1}}{\mathrm{2}}\:\Rightarrow\:\mathrm{lhs}\:<\mathrm{0}\:\Rightarrow\:−\frac{\mathrm{1}}{\mathrm{2}}<{x}<\mathrm{0}…