The differential equation of all lines perpendicular to the line $5 x+2 y+7=0$ is

The differential equation of all lines perpendicular to the line $5 x+2 y+7=0$ is
  1. 3dy-2dx=0
  2. 2dy-5dx=0
  3. 2dy-3dx=0
  4. 5dy-2dx=0

Solution

Given line $5 x+2 y+7=0$ has slope $\frac{-5}{2}$. Hence eq. of required line is $\begin{aligned} & y=\frac{2}{5} x+c \Rightarrow 2 x-5 y+c=0 \\ \therefore & 2-5 \frac{d y}{d x}=0 \Rightarrow 2=5 \frac{d y}{d x} \Rightarrow 2 d x=5 d y \Rightarrow 5 d y-2 d x=0 \end{aligned}$

Asked in: MHT CET 2020 (16 Oct Shift 1)

Practice more Differential Equations questions on Aicharya