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Category: Differentiation

nice-calculus-prove-that-cos-pix-2-cosh-pix-dx-1-2-

Question Number 140831 by mnjuly1970 last updated on 13/May/21 $$\:\:\:\:\:\:\:\: \\ $$$$\:\:\:\:\:\:\:\:\:\:……{nice}\:….\:{calculus}…… \\ $$$$\:\:\:\:\:{prove}\:\:{that}:: \\ $$$$\:\:\:\:\:\:\:\:\:\xi\::=\:\int_{−\infty} ^{\:\infty} \frac{{cos}\:\left(\pi{x}^{\mathrm{2}} \right)}{{cosh}\left(\pi{x}\right)}{dx}=\frac{\mathrm{1}}{\:\sqrt{\mathrm{2}}}\:…. \\ $$$$\:\:\:\:……. \\ $$ Answered by…

Let-consider-A-lim-x-0-0-1-t-x-dt-1-x-Prove-that-A-0-1-ln-t-dt-Deduce-the-value-of-A-

Question Number 75228 by ~blr237~ last updated on 08/Dec/19 $$\:\mathrm{Let}\:\mathrm{consider}\: \\ $$$$\mathrm{A}=\underset{{x}\rightarrow\mathrm{0}} {\mathrm{lim}}\:\left(\int_{\mathrm{0}} ^{\mathrm{1}} \left(\Gamma\left(\mathrm{t}\right)\right)^{\mathrm{x}} \mathrm{dt}\right)^{\frac{\mathrm{1}}{\mathrm{x}}} \\ $$$$\mathrm{Prove}\:\mathrm{that}\:\:\mathrm{A}=\int_{\mathrm{0}} ^{\mathrm{1}} \mathrm{ln}\left(\Gamma\left(\mathrm{t}\right)\right)\mathrm{dt}\:\: \\ $$$$\mathrm{Deduce}\:\mathrm{the}\:\mathrm{value}\:\mathrm{of}\:\mathrm{A} \\ $$ Commented…

Question-9686

Question Number 9686 by tawakalitu last updated on 24/Dec/16 Answered by mrW last updated on 24/Dec/16 $$\mathrm{u}=\mathrm{log}\:\left(\mathrm{x}^{\mathrm{2}} +\mathrm{y}^{\mathrm{2}} +\mathrm{z}^{\mathrm{2}} \right) \\ $$$$\frac{\mathrm{du}}{\mathrm{dy}}=\frac{\mathrm{2y}}{\mathrm{x}^{\mathrm{2}} +\mathrm{y}^{\mathrm{2}} +\mathrm{z}^{\mathrm{2}} }×\mathrm{log}\:\mathrm{e}…

Let-us-consider-the-function-F-x-0-1-e-x-ln-x-lnt-dt-1-Prove-that-for-all-x-1-F-x-exist-2-Prove-that-lim-t-0-tln-x-lnt-0-3-Prove-that-F-C-1-1-1-and-for-all-x-1-F-x-F-

Question Number 75220 by ~blr237~ last updated on 08/Dec/19 $$\mathrm{Let}\:\mathrm{us}\:\mathrm{consider}\:\mathrm{the}\:\mathrm{function}\: \\ $$$$\mathrm{F}\left(\mathrm{x}\right)=\int_{\mathrm{0}} ^{\mathrm{1}} \:\mathrm{e}^{−\mathrm{x}} \mathrm{ln}\left(\mathrm{x}−\mathrm{lnt}\right)\mathrm{dt}\: \\ $$$$\left.\mathrm{1}\right)\mathrm{Prove}\:\mathrm{that}\:\mathrm{for}\:\mathrm{all}\:\mathrm{x}\geqslant\mathrm{1}\:,\:\:\mathrm{F}\left(\mathrm{x}\right)\:\mathrm{exist} \\ $$$$\left.\mathrm{2}\right)\mathrm{Prove}\:\mathrm{that}\:\underset{\mathrm{t}\rightarrow\mathrm{0}} {\mathrm{lim}}\:\mathrm{tln}\left(\mathrm{x}−\mathrm{lnt}\right)=\mathrm{0} \\ $$$$\left.\mathrm{3}\right)\mathrm{Prove}\:\mathrm{that}\:\mathrm{F}\:\in\:\mathrm{C}^{\mathrm{1}} \left(\left[\mathrm{1}:\infty\left[,\left[\mathrm{1}:\infty\left[\right)\:\mathrm{and}\:\mathrm{for}\:\right.\right.\right.\right. \\ $$$$\mathrm{all}\:\mathrm{x}\geqslant\mathrm{1}\:\:\mathrm{F}\left(\mathrm{x}\right)=\mathrm{F}'\left(\mathrm{x}\right)+\mathrm{lnx}…

Let-m-n-be-given-positive-integers-If-x-amp-y-are-positive-numbers-such-that-x-y-S-S-is-a-constant-find-the-value-of-x-and-y-that-maximize-Q-x-m-y-n-

Question Number 140734 by liberty last updated on 12/May/21 $$\mathrm{Let}\:\mathrm{m},\mathrm{n}\:\mathrm{be}\:\mathrm{given}\:\mathrm{positive}\:\mathrm{integers}. \\ $$$$\mathrm{If}\:\mathrm{x}\:\&\:\mathrm{y}\:\mathrm{are}\:\mathrm{positive}\:\mathrm{numbers}\:\mathrm{such}\:\mathrm{that} \\ $$$$\mathrm{x}+\mathrm{y}=\:\mathrm{S}\:,\:\mathrm{S}\:\mathrm{is}\:\mathrm{a}\:\mathrm{constant},\:\mathrm{find} \\ $$$$\mathrm{the}\:\mathrm{value}\:\mathrm{of}\:\mathrm{x}\:\mathrm{and}\:\mathrm{y}\:\mathrm{that}\:\mathrm{maximize} \\ $$$$\mathrm{Q}=\mathrm{x}^{\mathrm{m}} \mathrm{y}^{\mathrm{n}} \:. \\ $$ Commented by mr…

Differential-system-x-x-y-z-ae-2t-y-y-z-x-be-2t-z-z-x-y-ce-2t-a-b-c-are-constants-help-me-

Question Number 140695 by Chhing last updated on 11/May/21 $$\mathrm{Differential}\:\mathrm{system} \\ $$$$\begin{cases}{\mathrm{x}'+\mathrm{x}−\mathrm{y}−\mathrm{z}=\mathrm{ae}^{\mathrm{2t}} }\\{\mathrm{y}'+\mathrm{y}−\mathrm{z}−\mathrm{x}=\mathrm{be}^{\mathrm{2t}} }\\{\mathrm{z}'+\mathrm{z}−\mathrm{x}−\mathrm{y}=\mathrm{ce}^{\mathrm{2t}} }\end{cases} \\ $$$$\:\mathrm{a},\mathrm{b},\mathrm{c}\:\mathrm{are}\:\mathrm{constants} \\ $$$$\mathrm{help}\:\mathrm{me} \\ $$ Answered by mr W…