61.28.35 problem 95

Internal problem ID [12516]
Book : Handbook of exact solutions for ordinary differential equations. By Polyanin and Zaitsev. Second edition
Section : Chapter 2, Second-Order Differential Equations. section 2.1.2-3
Problem number : 95
Date solved : Wednesday, March 05, 2025 at 07:08:38 PM
CAS classification : [[_2nd_order, _with_linear_symmetries]]

\begin{align*} x y^{\prime \prime }+\left (a \,x^{n}+b \right ) y^{\prime }+a \left (b -1\right ) x^{n -1} y&=0 \end{align*}

✓ Maple. Time used: 11.184 (sec). Leaf size: 143

ode:=x*diff(diff(y(x),x),x)+(a*x^n+b)*diff(y(x),x)+a*(b-1)*x^(n-1)*y(x) = 0; 
dsolve(ode,y(x), singsol=all);
 

\[ y = n \left (\left (b +n -1\right ) x^{-\frac {3 n}{2}+\frac {1}{2}-\frac {b}{2}}+a \,x^{-\frac {b}{2}-\frac {n}{2}+\frac {1}{2}}\right ) {\mathrm e}^{-\frac {a \,x^{n}}{2 n}} c_{2} \operatorname {WhittakerM}\left (\frac {b -n -1}{2 n}, \frac {b +2 n -1}{2 n}, \frac {a \,x^{n}}{n}\right )+x^{-\frac {3 n}{2}+\frac {1}{2}-\frac {b}{2}} {\mathrm e}^{-\frac {a \,x^{n}}{2 n}} c_{2} \left (b +n -1\right )^{2} \operatorname {WhittakerM}\left (\frac {b +n -1}{2 n}, \frac {b +2 n -1}{2 n}, \frac {a \,x^{n}}{n}\right )+c_{1} x^{1-b} \]

✓ Mathematica. Time used: 0.089 (sec). Leaf size: 90

ode=x*D[y[x],{x,2}]+(a*x^n+b)*D[y[x],x]+a*(b-1)*x^(n-1)*y[x]==0; 
ic={}; 
DSolve[{ode,ic},y[x],x,IncludeSingularSolutions->True]
 

\[ y(x)\to (-1)^{-\frac {b}{n}} n^{\frac {b-n-1}{n}} a^{\frac {1-b}{n}} \left (x^n\right )^{\frac {1-b}{n}} \left ((b-1) c_1 (-1)^{b/n} \Gamma \left (\frac {b-1}{n},0,\frac {a x^n}{n}\right )+c_2 (-1)^{\frac {1}{n}} n\right ) \]

✗ Sympy

from sympy import * 
x = symbols("x") 
a = symbols("a") 
b = symbols("b") 
n = symbols("n") 
y = Function("y") 
ode = Eq(a*x**(n - 1)*(b - 1)*y(x) + x*Derivative(y(x), (x, 2)) + (a*x**n + b)*Derivative(y(x), x),0) 
ics = {} 
dsolve(ode,func=y(x),ics=ics)
 

ValueError : Expected Expr or iterable but got None