46.4.1 problem 1

Internal problem ID [7328]
Book : ADVANCED ENGINEERING MATHEMATICS. ERWIN KREYSZIG, HERBERT KREYSZIG, EDWARD J. NORMINTON. 10th edition. John Wiley USA. 2011
Section : Chapter 5. Series Solutions of ODEs. Special Functions. Problem set 5.5. Bessel Functions Y(x). General Solution page 200
Problem number : 1
Date solved : Sunday, March 30, 2025 at 11:54:29 AM
CAS classification : [_Bessel]

\begin{align*} x^{2} y^{\prime \prime }+x y^{\prime }+\left (x^{2}-6\right ) y&=0 \end{align*}

Using series method with expansion around

\begin{align*} 0 \end{align*}

✓ Maple. Time used: 0.026 (sec). Leaf size: 89

Order:=6; 
ode:=x^2*diff(diff(y(x),x),x)+x*diff(y(x),x)+(x^2-6)*y(x) = 0; 
dsolve(ode,y(x),type='series',x=0);
 

\[ y = c_1 \,x^{-\sqrt {6}} \left (1+\frac {1}{-4+4 \sqrt {6}} x^{2}+\frac {1}{32} \frac {1}{\left (-2+\sqrt {6}\right ) \left (-1+\sqrt {6}\right )} x^{4}+\operatorname {O}\left (x^{6}\right )\right )+c_2 \,x^{\sqrt {6}} \left (1-\frac {1}{4+4 \sqrt {6}} x^{2}+\frac {1}{32} \frac {1}{\left (2+\sqrt {6}\right ) \left (1+\sqrt {6}\right )} x^{4}+\operatorname {O}\left (x^{6}\right )\right ) \]

✓ Mathematica. Time used: 0.004 (sec). Leaf size: 210

ode=x^2*D[y[x],{x,2}]+x*D[y[x],x]+(x^2-6)*y[x]==0; 
ic={}; 
AsymptoticDSolveValue[{ode,ic},y[x],{x,0,5}]
 

\[ y(x)\to c_2 \left (\frac {x^4}{\left (-4-\sqrt {6}+\left (1-\sqrt {6}\right ) \left (2-\sqrt {6}\right )\right ) \left (-2-\sqrt {6}+\left (3-\sqrt {6}\right ) \left (4-\sqrt {6}\right )\right )}-\frac {x^2}{-4-\sqrt {6}+\left (1-\sqrt {6}\right ) \left (2-\sqrt {6}\right )}+1\right ) x^{-\sqrt {6}}+c_1 \left (\frac {x^4}{\left (-4+\sqrt {6}+\left (1+\sqrt {6}\right ) \left (2+\sqrt {6}\right )\right ) \left (-2+\sqrt {6}+\left (3+\sqrt {6}\right ) \left (4+\sqrt {6}\right )\right )}-\frac {x^2}{-4+\sqrt {6}+\left (1+\sqrt {6}\right ) \left (2+\sqrt {6}\right )}+1\right ) x^{\sqrt {6}} \]

✗ Sympy

from sympy import * 
x = symbols("x") 
y = Function("y") 
ode = Eq(x**2*Derivative(y(x), (x, 2)) + x*Derivative(y(x), x) + (x**2 - 6)*y(x),0) 
ics = {} 
dsolve(ode,func=y(x),ics=ics,hint="2nd_power_series_regular",x0=0,n=6)
 

NotImplementedError : Not sure of sign of 6 - x0