Q. The differential equation representing the family of curves $y^{2} = 2c(x + \sqrt{c})$, where $c > 0$ is a parameter is of order and degree as follows

A) Order 2, degree 2
B) Order 1, degree 3
C) Order 1, degree 1
D) Order 1, degree 2
Explanation

(b)
Given, $y^{2} = 2c(x + \sqrt{c})$
$\Rightarrow$ $2yy_{1} = 2c$
$\Rightarrow$ $c = yy_{1}$
$\therefore$ $y^{2} = 2yy_{1}(x + \sqrt{yy_{1}})$
$\Rightarrow$ $y^{2} - 2yy_{1}x = \sqrt{yy_{1}}.2yy_{1}$
$\Rightarrow$ $\left( y^{2} - 2yy_{1}x \right)^{2} = 4\left( yy_{1} \right)^{3}$
$\therefore$ The degree of above equation is 3 and order is 1.

Dr. Abubacker
Reviewed by Dr. Abubacker

Physics Educator & NEET/JEE Specialist

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