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Category: Integration

let-U-n-1-nx-n-1-x-x-3-dx-with-n-1-1-find-U-n-interms-of-n-2-find-lim-n-U-n-3-study-the-serie-n-1-U-n-

Question Number 61232 by maxmathsup by imad last updated on 30/May/19 $${let}\:{U}_{{n}} =\int_{\mathrm{1}} ^{+\infty} \:\:\:\frac{\left[{nx}\right]−\left[\left({n}−\mathrm{1}\right){x}\right]}{{x}^{\mathrm{3}} }\:{dx}\:\:{with}\:{n}\geqslant\mathrm{1} \\ $$$$\left.\mathrm{1}\right)\:{find}\:{U}_{{n}} \:{interms}\:{of}\:{n} \\ $$$$\left.\mathrm{2}\right)\:{find}\:{lim}_{{n}\rightarrow+\infty} \:{U}_{{n}} \\ $$$$\left.\mathrm{3}\right)\:{study}\:{the}\:{serie}\:\sum_{{n}=\mathrm{1}} ^{\infty}…

let-f-n-a-0-a-x-n-a-2-x-2-dx-with-a-gt-0-1-determine-a-explicit-form-of-f-a-2-let-g-n-a-f-a-give-g-n-a-at-form-of-integral-and-give-its-value-3-find-the-value-of-0-2-

Question Number 61229 by maxmathsup by imad last updated on 30/May/19 $${let}\:{f}_{{n}} \left({a}\right)\:=\int_{\mathrm{0}} ^{{a}} \:{x}^{{n}} \sqrt{{a}^{\mathrm{2}} −{x}^{\mathrm{2}} }{dx}\:\:{with}\:{a}>\mathrm{0} \\ $$$$\left.\mathrm{1}\right)\:{determine}\:{a}\:{explicit}\:{form}\:{of}\:{f}\left({a}\right) \\ $$$$\left.\mathrm{2}\right)\:{let}\:{g}_{{n}} \left({a}\right)\:={f}^{'} \left({a}\right)\:\:\:{give}\:{g}_{{n}} \left({a}\right)\:{at}\:{form}\:{of}\:{integral}\:{and}\:{give}\:{its}…

sin-x-cos-x-3sin-x-4cos-x-1-dx-

Question Number 126753 by bemath last updated on 24/Dec/20 $$\:\:\int\:\frac{\mathrm{sin}\:{x}+\mathrm{cos}\:{x}}{\mathrm{3sin}\:{x}+\mathrm{4cos}\:{x}+\mathrm{1}}\:{dx}\: \\ $$ Answered by Ar Brandon last updated on 24/Dec/20 $$\mathrm{sinx}+\mathrm{cosx}=\lambda\left(\mathrm{3sinx}+\mathrm{4cosx}+\mathrm{1}\right)+\mu\left\{\frac{\mathrm{d}}{\mathrm{dx}}\left(\mathrm{3sinx}+\mathrm{4cosx}+\mathrm{1}\right)\right\}+\gamma \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:=\lambda\left(\mathrm{3sinx}+\mathrm{4cosx}+\mathrm{1}\right)+\mu\left(\mathrm{3cosx}−\mathrm{4sinx}\right)+\gamma \\ $$$$\begin{cases}{\mathrm{3}\lambda−\mathrm{4}\mu=\mathrm{1}}\\{\mathrm{4}\lambda+\mathrm{3}\mu=\mathrm{1}}\\{\lambda+\gamma=\mathrm{0}}\end{cases}\Rightarrow\begin{cases}{\mathrm{25}\mu=−\mathrm{1}}\\{\mathrm{25}\lambda=\mathrm{7}}\\{\gamma=−\lambda}\end{cases}…

Question-126749

Question Number 126749 by bemath last updated on 24/Dec/20 Commented by MJS_new last updated on 24/Dec/20 $${t}=\mathrm{tan}\:\frac{{x}}{\mathrm{2}}\:\mathrm{leads}\:\mathrm{to} \\ $$$$\mathrm{2}\int\frac{\left({t}+\mathrm{1}\right)^{\mathrm{2}} }{{t}^{\mathrm{4}} +\mathrm{10}{t}^{\mathrm{2}} +\mathrm{1}}{dt} \\ $$$$\mathrm{now}\:\mathrm{find}\:\mathrm{the}\:\mathrm{2}\:\mathrm{square}\:\mathrm{factors}\:\mathrm{of}\:\mathrm{the}\:\mathrm{denominator} \\…

dx-tan-5-x-1-

Question Number 126746 by bemath last updated on 24/Dec/20 $$\:\:\int\:\frac{{dx}}{\mathrm{tan}\:^{\mathrm{5}} {x}+\mathrm{1}}\:? \\ $$ Commented by MJS_new last updated on 24/Dec/20 $${t}=\mathrm{tan}\:{x}\:\mathrm{leads}\:\mathrm{to} \\ $$$$\int\frac{{dt}}{\left({t}^{\mathrm{2}} +\mathrm{1}\right)\left({t}^{\mathrm{5}} +\mathrm{1}\right)}…

Question-61208

Question Number 61208 by Tawa1 last updated on 30/May/19 Commented by maxmathsup by imad last updated on 30/May/19 $${its}\:{only}\:{a}\:{try}\:{let}\:{f}\left({t}\right)\:=\int_{\mathrm{0}} ^{\infty} \:\frac{{ln}\left(\mathrm{1}+{tx}^{\mathrm{2}} \right)}{\mathrm{1}+{x}^{\mathrm{4}} }\:{dx}\:\:{with}\:{t}\:\geqslant\mathrm{0} \\ $$$${we}\:{have}\:{f}^{'}…