Question and Answers Forum

All Questions      Topic List

Differential Equation Questions

Previous in All Question      Next in All Question      

Previous in Differential Equation      Next in Differential Equation      

Question Number 131466 by Ahmed1hamouda last updated on 05/Feb/21

Commented by Ahmed1hamouda last updated on 05/Feb/21

  solve the differential equation n)D

$$ \\ $$$$\left.\mathrm{solve}\:\mathrm{the}\:\mathrm{differential}\:\mathrm{equation}\:\mathrm{n}\right)\mathrm{D} \\ $$

Answered by EDWIN88 last updated on 05/Feb/21

(dy/dx) + ((y ln x)/x) = y.e^x    (dy/dx) = y(e^x −((ln x)/x))   (dy/y) = (e^x −((ln x)/x))dx   ln y = e^x −(1/2)ln^2 (x)+c   ln y^2 +(ln x)^2 =2e^x +C

$$\frac{{dy}}{{dx}}\:+\:\frac{{y}\:\mathrm{ln}\:{x}}{{x}}\:=\:{y}.{e}^{{x}} \\ $$$$\:\frac{{dy}}{{dx}}\:=\:{y}\left({e}^{{x}} −\frac{\mathrm{ln}\:{x}}{{x}}\right) \\ $$$$\:\frac{{dy}}{{y}}\:=\:\left({e}^{{x}} −\frac{\mathrm{ln}\:{x}}{{x}}\right){dx} \\ $$$$\:\mathrm{ln}\:{y}\:=\:{e}^{{x}} −\frac{\mathrm{1}}{\mathrm{2}}\mathrm{ln}\:^{\mathrm{2}} \left({x}\right)+{c} \\ $$$$\:\mathrm{ln}\:{y}^{\mathrm{2}} +\left(\mathrm{ln}\:{x}\right)^{\mathrm{2}} =\mathrm{2}{e}^{{x}} +{C} \\ $$$$ \\ $$

Commented by Ahmed1hamouda last updated on 05/Feb/21

(dy/dx)+((yln(y))/x)=y.e^x   (1/y).(dy/dx)=((ln(y))/x)=e^x   ln(y)=u ∴(1/y).(dy/dx)=(du/dx)  (du/dx)+(u/x)=e^x →I.F.=e^(∫(1/x)dx) =e^(ln(x)) =x  ux=∫xe^x .dx→xln(y)=xe^x −e^x +c

$$\frac{\boldsymbol{{dy}}}{\boldsymbol{{dx}}}+\frac{\boldsymbol{{yln}}\left(\boldsymbol{{y}}\right)}{\boldsymbol{{x}}}=\boldsymbol{{y}}.\boldsymbol{{e}}^{\boldsymbol{{x}}} \\ $$$$\frac{\mathrm{1}}{\boldsymbol{{y}}}.\frac{\boldsymbol{{dy}}}{\boldsymbol{{dx}}}=\frac{\boldsymbol{{ln}}\left(\boldsymbol{{y}}\right)}{\boldsymbol{{x}}}=\boldsymbol{{e}}^{\boldsymbol{{x}}} \\ $$$$\boldsymbol{{ln}}\left(\boldsymbol{{y}}\right)=\boldsymbol{{u}}\:\therefore\frac{\mathrm{1}}{\boldsymbol{{y}}}.\frac{\boldsymbol{{dy}}}{\boldsymbol{{dx}}}=\frac{\boldsymbol{{du}}}{\boldsymbol{{dx}}} \\ $$$$\frac{\boldsymbol{{du}}}{\boldsymbol{{dx}}}+\frac{\boldsymbol{{u}}}{\boldsymbol{{x}}}=\boldsymbol{{e}}^{\boldsymbol{{x}}} \rightarrow\mathrm{I}.\mathrm{F}.=\boldsymbol{{e}}^{\int\frac{\mathrm{1}}{\boldsymbol{{x}}}\boldsymbol{{dx}}} =\boldsymbol{{e}}^{\boldsymbol{{ln}}\left(\boldsymbol{{x}}\right)} =\boldsymbol{{x}} \\ $$$$\boldsymbol{{ux}}=\int\boldsymbol{{xe}}^{\boldsymbol{{x}}} .\boldsymbol{{dx}}\rightarrow\boldsymbol{{xln}}\left(\boldsymbol{{y}}\right)=\boldsymbol{{xe}}^{\boldsymbol{{x}}} −\boldsymbol{{e}}^{\boldsymbol{{x}}} +\boldsymbol{{c}} \\ $$

Terms of Service

Privacy Policy

Contact: info@tinkutara.com