The general solution of the differential equation $\frac{d y}{d x}+\frac{2}{x} y=x^2$ is

The general solution of the differential equation $\frac{d y}{d x}+\frac{2}{x} y=x^2$ is
  1. $y=c x^{-3}-\frac{x^2}{4}$
  2. $y=c x^3-\frac{x^2}{4}$
  3. $y=c x^2+\frac{x^3}{5}$
  4. $y=c x^{-2}+\frac{x^3}{5}$

Solution

Given differential equation is $ \frac{d y}{d x}+\frac{2}{x} \cdot y=x^2 $ This is of the linear form. $ \begin{aligned} & \therefore P=\frac{2}{x}, Q=x^2 \\ & \text { I.F }=e^{\int \frac{2}{x} d x}=e^{\log x^2}=x^2 \end{aligned} $ Solution is $ \begin{aligned} & y \cdot x^2=\int x^2 \cdot x^2 d x+c=\frac{x^5}{5}+c \\ & y=\frac{x^3}{5}+c x^{-2} \end{aligned} $

Asked in: JEE Main 2012 (19 May Online)

Practice more Differential Equations questions on Aicharya