Q. The differential equation whose solution is $Ax^{2} + By^{2} = 1$, where $A$ and $B$ are arbitrary constants, is of

A) First order and second degree
B) First order and first degree
C) Second order and first degree
D) Second order and second degree
Explanation

(c)
The given equation is $Ax^{2} + By^{2} = 1$
$\Rightarrow$ $2Ax + 2By\ \frac{dy}{dx} = 0$ …(i)
$\Rightarrow$ $2A + 2B\left\{ \left( \frac{dy}{dx} \right)^{2} + y\ \frac{d^{2}y}{dx^{2}} \right\} = 0$ …(ii)
Eliminating A and B from Eqs. (i) and (ii), we get
$y\ \frac{d^{2}y}{dx^{2}} + \left( \frac{dy}{dx} \right)^{2} - \frac{y}{x}.\ \frac{dy}{dx} = 0$
Here, order =2, degree =1

Dr. Abubacker
Reviewed by Dr. Abubacker

Physics Educator & NEET/JEE Specialist

Ph.D. in Physics with 19+ years of teaching experience.