ax² + by² = 1

Since it has two arbitrary constants, we differentiate it twice w.r.t x

Differentiate w.r.t x

--(1)

Again, differentiate w.r.t x

Applying product rule

Put value of a in (1) we get,

Which is ⇒ xyy₂ + xy₁² – yy₁ = 0 =(B)