4 1  Procedure to form a differential equation that will represent a given
family of curves
(a)
If the given family F1 of curves depends on only one parameter then it is
represented by an equation of the form
F1 (x, y, a) = 0 (1)
For example, the family of parabolas y2 = ax can be represented by an equation
of the form f (x, y, a) : y2 = ax Differentiating equation (1) with respect to x, we get an equation involving
y′, y, x, and a, i