6.16.28 problem 24

Internal problem ID [2090]
Book : Elementary differential equations with boundary value problems. William F. Trench. Brooks/Cole 2001
Section : Chapter 7 Series Solutions of Linear Second Equations. 7.6 THE METHOD OF FROBENIUS III. Exercises 7.7. Page 389
Problem number : 24
Date solved : Tuesday, September 30, 2025 at 05:23:45 AM
CAS classification : [[_2nd_order, _with_linear_symmetries]]

\begin{align*} x^{2} y^{\prime \prime }-x \left (-x^{2}+7\right ) y^{\prime }+12 y&=0 \end{align*}

Using series method with expansion around

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

✓ Maple. Time used: 0.024 (sec). Leaf size: 46

Order:=6; 
ode:=x^2*diff(diff(y(x),x),x)-x*(-x^2+7)*diff(y(x),x)+12*y(x) = 0; 
dsolve(ode,y(x),type='series',x=0);
 

\[ y = x^{2} \left (c_1 \,x^{4} \left (1-\frac {1}{2} x^{2}+\frac {1}{8} x^{4}+\operatorname {O}\left (x^{6}\right )\right )+c_2 \left (\left (72 x^{4}+\operatorname {O}\left (x^{6}\right )\right ) \ln \left (x \right )+\left (-144-72 x^{2}+54 x^{4}+\operatorname {O}\left (x^{6}\right )\right )\right )\right ) \]

✓ Mathematica. Time used: 0.006 (sec). Leaf size: 55

ode=x^2*D[y[x],{x,2}]-x*(7-x^2)*D[y[x],x]+12*y[x]==0; 
ic={}; 
AsymptoticDSolveValue[{ode,ic},y[x],{x,0,5}]
 

\[ y(x)\to c_2 \left (\frac {x^{10}}{8}-\frac {x^8}{2}+x^6\right )+c_1 \left (-\frac {1}{2} x^6 \log (x)-\frac {1}{4} \left (x^4-2 x^2-4\right ) x^2\right ) \]

✗ Sympy

from sympy import * 
x = symbols("x") 
y = Function("y") 
ode = Eq(x**2*Derivative(y(x), (x, 2)) - x*(7 - x**2)*Derivative(y(x), x) + 12*y(x),0) 
ics = {} 
dsolve(ode,func=y(x),ics=ics,hint="2nd_power_series_regular",x0=0,n=6)
 

ValueError : Expected Expr or iterable but got None