45.2.31 problem 31

Internal problem ID [7254]
Book : A FIRST COURSE IN DIFFERENTIAL EQUATIONS with Modeling Applications. Dennis G. Zill. 9th edition. Brooks/Cole. CA, USA.
Section : Chapter 6. SERIES SOLUTIONS OF LINEAR EQUATIONS. Exercises. 6.2 page 239
Problem number : 31
Date solved : Wednesday, March 05, 2025 at 04:22:00 AM
CAS classification : [[_2nd_order, _with_linear_symmetries]]

\begin{align*} x y^{\prime \prime }+\left (x -6\right ) y^{\prime }-3 y&=0 \end{align*}

Using series method with expansion around

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

✓ Maple. Time used: 0.009 (sec). Leaf size: 40

Order:=6; 
ode:=x*diff(diff(y(x),x),x)+(x-6)*diff(y(x),x)-3*y(x) = 0; 
dsolve(ode,y(x),type='series',x=0);
 

\[ y = c_{1} x^{7} \left (1-\frac {1}{2} x +\frac {5}{36} x^{2}-\frac {1}{36} x^{3}+\frac {7}{1584} x^{4}-\frac {7}{11880} x^{5}+\operatorname {O}\left (x^{6}\right )\right )+c_{2} \left (3628800-1814400 x +362880 x^{2}-30240 x^{3}+\operatorname {O}\left (x^{6}\right )\right ) \]

✓ Mathematica. Time used: 0.028 (sec). Leaf size: 63

ode=x*D[y[x],{x,2}]+(x-6)*D[y[x],x]-3*y[x]==0; 
ic={}; 
AsymptoticDSolveValue[{ode,ic},y[x],{x,0,5}]
 

\[ y(x)\to c_1 \left (-\frac {x^3}{120}+\frac {x^2}{10}-\frac {x}{2}+1\right )+c_2 \left (\frac {7 x^{11}}{1584}-\frac {x^{10}}{36}+\frac {5 x^9}{36}-\frac {x^8}{2}+x^7\right ) \]

✗ Sympy

from sympy import * 
x = symbols("x") 
y = Function("y") 
ode = Eq(x*Derivative(y(x), (x, 2)) + (x - 6)*Derivative(y(x), x) - 3*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