Here is the question I refer to I need help solving a differential equation
I am not the author of the question, it is just we face same problem. I was given a differential equation $y'= x^2 + y^2$. Letting $y(x)=\frac{-f(x)}{f(x)}$ gives us \begin{equation}f''+x^2f=0\end{equation} This is where I got stuck. The answer in the question stated that the ODE can be transformed to ODE of Bessel kind. However, I am not sure on how to do this since the ODE does not actually has form
$$x^2\frac{d^2y}{dx^2} + x\frac{dy}{dx}+(x^2-v^2)y = 0$$ which is a Bessel Equation. Any help appreciated.
HINT :
The change of function : $\quad y(x)=x^\alpha J_\nu(\beta x^\gamma)\quad$ leads to a generalized form of Bessel equation. Then, identification to the standard form of Bessel equation determines the parameters $\alpha,\beta,\gamma,\nu$.
http://mathworld.wolfram.com/BesselDifferentialEquation.html