90.30.9 problem 9

Internal problem ID [25449]
Book : Ordinary Differential Equations. By William Adkins and Mark G Davidson. Springer. NY. 2010. ISBN 978-1-4614-3617-1
Section : Chapter 7. Power series methods. Exercises at page 517
Problem number : 9
Date solved : Friday, October 03, 2025 at 12:01:37 AM
CAS classification : [[_2nd_order, _with_linear_symmetries]]

\begin{align*} \left (t^{2}+1\right ) y^{\prime \prime }-4 t y^{\prime }+6 y&=0 \end{align*}

Using series method with expansion around

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

✓ Maple. Time used: 0.003 (sec). Leaf size: 25

Order:=6; 
ode:=(t^2+1)*diff(diff(y(t),t),t)-4*t*diff(y(t),t)+6*y(t) = 0; 
dsolve(ode,y(t),type='series',t=0);
 

\[ y = y \left (0\right )+t y^{\prime }\left (0\right )-3 y \left (0\right ) t^{2}-\frac {y^{\prime }\left (0\right ) t^{3}}{3} \]

✓ Mathematica. Time used: 0.001 (sec). Leaf size: 26

ode=(1+t^2)*D[y[t],{t,2}]-4*t*D[y[t],t]+6*y[t]==0; 
ic={}; 
AsymptoticDSolveValue[{ode,ic},y[t],{t,0,5}]
 

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

✓ Sympy. Time used: 0.251 (sec). Leaf size: 24

from sympy import * 
t = symbols("t") 
y = Function("y") 
ode = Eq(-4*t*Derivative(y(t), t) + (t**2 + 1)*Derivative(y(t), (t, 2)) + 6*y(t),0) 
ics = {} 
dsolve(ode,func=y(t),ics=ics,hint="2nd_power_series_ordinary",x0=0,n=6)
 

\[ y{\left (t \right )} = C_{2} \left (1 - 3 t^{2}\right ) + C_{1} t \left (1 - \frac {t^{2}}{3}\right ) + O\left (t^{6}\right ) \]