Internal
problem
ID
[11530]
Book
:
Differential
Gleichungen,
E.
Kamke,
3rd
ed.
Chelsea
Pub.
NY,
1948
Section
:
Chapter
4,
linear
fourth
order
Problem
number
:
1570
Date
solved
:
Sunday, March 30, 2025 at 08:24:16 PM
CAS
classification
:
[[_high_order, _with_linear_symmetries]]
ode:=x^4*diff(diff(diff(diff(y(x),x),x),x),x)+(6-4*a-4*c)*x^3*diff(diff(diff(y(x),x),x),x)+(-2*nu^2*c^2+2*a^2+4*(a+c-1)^2+4*(a-1)*(c-1)-1)*x^2*diff(diff(y(x),x),x)+(2*nu^2*c^2-2*a^2-(2*a-1)*(2*c-1))*(2*a+2*c-1)*x*diff(y(x),x)+((-c^2*nu^2+a^2)*(-c^2*nu^2+a^2+4*a*c+4*c^2)-b^4*c^4*x^(4*c))*y(x) = 0; dsolve(ode,y(x), singsol=all);
ode=((a^2 - c^2*\[Nu]^2)*(a^2 + 4*a*c + 4*c^2 - c^2*\[Nu]^2) - b^4*c^4*x^(4*c))*y[x] + (-1 + 2*a + 2*c)*(-2*a^2 - (-1 + 2*a)*(-1 + 2*c) + 2*c^2*\[Nu]^2)*x*D[y[x],x] + (-1 + 2*a^2 + 4*(-1 + a)*(-1 + c) + 4*(-1 + a + c)^2 - 2*c^2*\[Nu]^2)*x^2*D[y[x],{x,2}] + (6 - 4*a - 4*c)*x^3*Derivative[3][y][x] + x^4*Derivative[4][y][x] == 0; ic={}; DSolve[{ode,ic},y[x],x,IncludeSingularSolutions->True]
from sympy import * x = symbols("x") a = symbols("a") b = symbols("b") c = symbols("c") nu = symbols("nu") y = Function("y") ode = Eq(x**4*Derivative(y(x), (x, 4)) + x**3*(-4*a - 4*c + 6)*Derivative(y(x), (x, 3)) + x**2*(2*a**2 - 2*c**2*nu**2 + (4*a - 4)*(c - 1) + 4*(a + c - 1)**2 - 1)*Derivative(y(x), (x, 2)) + x*(2*a + 2*c - 1)*(-2*a**2 + 2*c**2*nu**2 - (2*a - 1)*(2*c - 1))*Derivative(y(x), x) + (-b**4*c**4*x**(4*c) + (a**2 - c**2*nu**2)*(a**2 + 4*a*c - c**2*nu**2 + 4*c**2))*y(x),0) ics = {} dsolve(ode,func=y(x),ics=ics)
NotImplementedError : The given ODE Derivative(y(x), x) - (a**4*y(x) + 4*a**3*c*y(x) - 2*a**2*c**2*nu**2*y(x) + 4*a**2*c**2*y(x) + 6*a**2*x**2*Derivative(y(x), (x, 2)) - 4*a*c**3*nu**2*y(x) + 12*a*c*x**2*Derivative(y(x), (x, 2)) - 4*a*x**3*Derivative(y(x), (x, 3)) - 12*a*x**2*Derivative(y(x), (x, 2)) - b**4*c**4*x**(4*c)*y(x) + c**4*nu**4*y(x) - 4*c**4*nu**2*y(x) - 2*c**2*nu**2*x**2*Derivative(y(x), (x, 2)) + 4*c**2*x**2*Derivative(y(x), (x, 2)) - 4*c*x**3*Derivative(y(x), (x, 3)) - 12*c*x**2*Derivative(y(x), (x, 2)) + x**4*Derivative(y(x), (x, 4)) + 6*x**3*Derivative(y(x), (x, 3)) + 7*x**2*Derivative(y(x), (x, 2)))/(x*(4*a**3 + 12*a**2*c - 6*a**2 - 4*a*c**2*nu**2 + 8*a*c**2 - 12*a*c + 4*a - 4*c**3*nu**2 + 2*c**2*nu**2 - 4*c**2 + 4*c - 1)) cannot be solved by the factorable group method