Practicing Success
The general solution of the differential equation $[2\sqrt{xy}-x]dy+ydx=0$ is: |
$\log x+\sqrt{\frac{y}{x}}=c$ $\log y-\sqrt{\frac{x}{y}}=c$ $\log y+\sqrt{\frac{x}{y}}=c$ None of these |
$\log y+\sqrt{\frac{x}{y}}=c$ |
$\frac{dy}{dx}=\frac{\frac{y}{x}}{1-2\sqrt{\frac{y}{x}}}$ put $\frac{y}{x}=v⇒\frac{dy}{dx}=x.\frac{dv}{dx}+v⇒\int\frac{dx}{x}=\int\frac{1-2\sqrt{v}}{2v^{3/2}}dv$ $⇒-c+\log x=-v^{-1/2}-\log v$ $⇒\log y+\sqrt{\frac{x}{y}}=c$ |