The question asks to find the singular points of the Differential Equation and to classify each of them as regular/irregular:
$x(x^2+1)^2y''+y=0$
Edit: I gave it another shot and I ended up with 3 singular points:
$x=0$ (regular singular point)
$x=+i$ (irregular singular point)
$x=-i$ (irregular singular point)
Could you kindly let me know if I found the correct solution? Thank you for your time.