Solve the differential equation: $ydx + (x - y^2) dy = 0$ |
$x = y^2 + Cy$ $xy = \frac{y^3}{3} + C$ $y = \frac{x^2}{3} + \frac{C}{x}$ $3xy + y^3 = C$ |
$xy = \frac{y^3}{3} + C$ |
The correct answer is Option (2) → $xy = \frac{y^3}{3} + C$ ## $ydx + (x - y^2) dy = 0$ Reducing the given differential equation to the form $\frac{dx}{dy} + Px = Q$ we get, $\frac{dx}{dy} + \frac{x}{y} = y$ $I.F. = e^{\int P dy} = e^{\int \frac{1}{y} dy} = e^{\log y} = y$ The general solution is given by $x \cdot I.F. = \int Q \cdot I.F. \, dy \Rightarrow xy = \int y^2 dy$ $\Rightarrow xy = \frac{y^3}{3} + C, \text{ which is the required general solution}$ |