Question

For a ∈ (−2π, 0), consider the differential equation
$x^2\frac{d^2y}{dx^2}+ax\frac{dy}{dx}+y=0$ for x > 0.
Let D be the set of all a ∈ (−2π, 0) for which all corresponding real solutions to the above differential equation approach zero as x → 0+. Then, the number of elements in D ∩ $\Z$ equals ___________

Answer 1

The correct answer is 6.