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Category: Differential Equation

x-tan-y-x-y-sec-2-y-x-dx-x-sec-2-y-x-dy-0-

Question Number 105738 by bobhans last updated on 31/Jul/20 $$\left({x}\:\mathrm{tan}\:\left(\frac{{y}}{{x}}\right)−{y}\:\mathrm{sec}\:^{\mathrm{2}} \left(\frac{{y}}{{x}}\right)\right)\:{dx}−{x}\:\mathrm{sec}\:^{\mathrm{2}} \left(\frac{{y}}{{x}}\right){dy}=\mathrm{0} \\ $$ Answered by john santu last updated on 01/Aug/20 $${set}\:\frac{{y}}{{x}}\:=\:\vartheta\:\Rightarrow{y}=\vartheta{x} \\ $$$$\frac{{dy}}{{dx}}\:=\:\vartheta\:+\:{x}\:\frac{{d}\vartheta}{{dx}}…

Given-I-n-0-1-1-x-n-n-e-x-dx-n-N-a-Show-that-x-0-1-1-x-n-e-x-e-and-deduce-that-the-Sequence-I-n-n-converges-to-zero-b-Establish-a-recurrence-relation-between-I-n-and-I-n-

Question Number 105632 by Ar Brandon last updated on 30/Jul/20 $$\mathrm{Given}\:\mathrm{I}_{\mathrm{n}} =\int_{\mathrm{0}} ^{\mathrm{1}} \frac{\left(\mathrm{1}−\mathrm{x}\right)^{\mathrm{n}} }{\mathrm{n}!}\mathrm{e}^{\mathrm{x}} \mathrm{dx}\:,\:\mathrm{n}\in\mathbb{N} \\ $$$$\mathrm{a}\backslash\mathrm{Show}\:\mathrm{that}\:\forall\mathrm{x}\in\left[\mathrm{0},\mathrm{1}\right],\:\left(\mathrm{1}−\mathrm{x}\right)^{\mathrm{n}} \mathrm{e}^{\mathrm{x}} \leqslant\mathrm{e}\:\mathrm{and}\:\mathrm{deduce}\:\mathrm{that}\:\mathrm{the}\: \\ $$$$\mathrm{Sequence}\:\left(\mathrm{I}_{\mathrm{n}} \right)_{\mathrm{n}} \:\mathrm{converges}\:\mathrm{to}\:\mathrm{zero}. \\…

d-2-y-dx-2-4-dy-dx-y-a-sin-2x-

Question Number 105603 by bemath last updated on 30/Jul/20 $$\frac{{d}^{\mathrm{2}} {y}}{{dx}^{\mathrm{2}} }−\mathrm{4}\frac{{dy}}{{dx}}+{y}\:=\:{a}\:\mathrm{sin}\:\mathrm{2}{x} \\ $$ Answered by bobhans last updated on 30/Jul/20 $$\mathcal{H}{omogenous}\:{equation} \\ $$$$\nu^{\mathrm{2}} −\mathrm{4}\nu+\mathrm{1}=\mathrm{0}\:\rightarrow\nu=\frac{\mathrm{4}\pm\mathrm{2}\sqrt{\mathrm{3}}}{\mathrm{2}}…