68.15.20 problem 20

Internal problem ID [17746]
Book : INTRODUCTORY DIFFERENTIAL EQUATIONS. Martha L. Abell, James P. Braselton. Fourth edition 2014. ElScAe. 2014
Section : Chapter 4. Higher Order Equations. Exercises 4.7, page 195
Problem number : 20
Date solved : Thursday, October 02, 2025 at 02:27:36 PM
CAS classification : [[_high_order, _missing_y]]

\begin{align*} x^{3} y^{\prime \prime \prime \prime }+6 x^{2} y^{\prime \prime \prime }+7 x y^{\prime \prime }+y^{\prime }&=0 \end{align*}

✓ Maple. Time used: 0.002 (sec). Leaf size: 22

ode:=x^3*diff(diff(diff(diff(y(x),x),x),x),x)+6*x^2*diff(diff(diff(y(x),x),x),x)+7*x*diff(diff(y(x),x),x)+diff(y(x),x) = 0; 
dsolve(ode,y(x), singsol=all);
 

\[ y = c_4 \ln \left (x \right )^{3}+c_3 \ln \left (x \right )^{2}+c_2 \ln \left (x \right )+c_1 \]

✓ Mathematica. Time used: 0.006 (sec). Leaf size: 33

ode=x^3*D[y[x],{x,4}]+6*x^2*D[y[x],{x,3}]+7*x*D[y[x],{x,2}]+D[y[x],x]==0; 
ic={}; 
DSolve[{ode,ic},y[x],x,IncludeSingularSolutions->True]
 

\begin{align*} y(x)&\to \frac {1}{3} c_3 \log ^3(x)+\frac {1}{2} c_2 \log ^2(x)+c_1 \log (x)+c_4 \end{align*}

✓ Sympy. Time used: 0.118 (sec). Leaf size: 22

from sympy import * 
x = symbols("x") 
y = Function("y") 
ode = Eq(x**3*Derivative(y(x), (x, 4)) + 6*x**2*Derivative(y(x), (x, 3)) + 7*x*Derivative(y(x), (x, 2)) + Derivative(y(x), x),0) 
ics = {} 
dsolve(ode,func=y(x),ics=ics)
 

\[ y{\left (x \right )} = C_{1} + C_{2} \log {\left (x \right )} + C_{3} \log {\left (x \right )}^{2} + C_{4} \log {\left (x \right )}^{3} \]