Question
Question: The differential equation representing the family of hyperbola a<sup>2</sup>x<sup>2</sup> –b<sup>2</...
The differential equation representing the family of hyperbola a2x2 –b2y2 = c2 is –
A
y′y′′ + yy′ = x1
B
y′y′′ + yy′ = x21
C
y′y′′ – yy′ = x1
D
y′y′′ = y′y – x1
Answer
y′y′′ + yy′ = x1
Explanation
Solution
Differentiating the equation twice w.r.t. x, we have
2a2 x – 2b2yy' = 0, a2 – b2(y'2 + yy'') = 0
Eliminating a2 and b2 we have the differential equation
y′y′′+yy′=x1