60.4.24 problem 1480

Internal problem ID [11447]
Book : Differential Gleichungen, E. Kamke, 3rd ed. Chelsea Pub. NY, 1948
Section : Chapter 3, linear third order
Problem number : 1480
Date solved : Sunday, March 30, 2025 at 08:22:24 PM
CAS classification : [[_3rd_order, _with_linear_symmetries]]

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

✓ Maple. Time used: 0.010 (sec). Leaf size: 54

ode:=x*diff(diff(diff(y(x),x),x),x)-(x+2*v)*diff(diff(y(x),x),x)-(x-2*v-1)*diff(y(x),x)+(x-1)*y(x) = 0; 
dsolve(ode,y(x), singsol=all);
 

\[ y = \frac {x^{2+v} c_2 \operatorname {BesselI}\left (-v +1, x\right )-2 \operatorname {BesselI}\left (-v , x\right ) x^{v +1} c_2 v +x^{2+v} c_3 \operatorname {BesselK}\left (v +1, x\right )+c_1 \,{\mathrm e}^{x} x}{x} \]

✓ Mathematica. Time used: 0.11 (sec). Leaf size: 114

ode=(-1 + x)*y[x] - (-1 - 2*v + x)*D[y[x],x] - (2*v + x)*D[y[x],{x,2}] + x*Derivative[3][y][x] == 0; 
ic={}; 
DSolve[{ode,ic},y[x],x,IncludeSingularSolutions->True]
 

\[ y(x)\to e^x \left (c_2 \int _1^x\exp \left (\int _1^{K[2]}\frac {2 v-2 K[1]+1}{K[1]}dK[1]\right ) \operatorname {HypergeometricU}\left (v+\frac {1}{2},2 v+2,2 K[2]\right )dK[2]+c_3 \int _1^x\exp \left (\int _1^{K[3]}\frac {2 v-2 K[1]+1}{K[1]}dK[1]\right ) L_{-v-\frac {1}{2}}^{2 v+1}(2 K[3])dK[3]+c_1\right ) \]

✗ Sympy

from sympy import * 
x = symbols("x") 
v = symbols("v") 
y = Function("y") 
ode = Eq(x*Derivative(y(x), (x, 3)) - (2*v + x)*Derivative(y(x), (x, 2)) + (x - 1)*y(x) - (-2*v + x - 1)*Derivative(y(x), x),0) 
ics = {} 
dsolve(ode,func=y(x),ics=ics)
 

NotImplementedError : The given ODE Derivative(y(x), x) - (2*v*Derivative(y(x), (x, 2)) - x*y(x) + x*Derivative(y(x), (x, 2)) - x*Derivative(y(x), (x, 3)) + y(x))/(2*v - x + 1) cannot be solved by the factorable group method