32.7.17 problem Exercise 20.18, page 220

Internal problem ID [5932]
Book : Ordinary Differential Equations, By Tenenbaum and Pollard. Dover, NY 1963
Section : Chapter 4. Higher order linear differential equations. Lesson 20. Constant coefficients
Problem number : Exercise 20.18, page 220
Date solved : Monday, January 27, 2025 at 01:27:42 PM
CAS classification : [[_high_order, _missing_x]]

\begin{align*} y^{\prime \prime \prime \prime }+3 y^{\prime \prime \prime }&=0 \end{align*}

✓ Solution by Maple

Time used: 0.003 (sec). Leaf size: 20

dsolve(diff(y(x),x$4)+3*diff(y(x),x$3)=0,y(x), singsol=all)
 

\[ y \left (x \right ) = c_{1} +c_{2} x +c_3 \,x^{2}+c_4 \,{\mathrm e}^{-3 x} \]

✓ Solution by Mathematica

Time used: 0.029 (sec). Leaf size: 28

DSolve[D[y[x],{x,4}]+3*D[y[x],{x,3}]==0,y[x],x,IncludeSingularSolutions -> True]
 

\[ y(x)\to -\frac {1}{27} c_1 e^{-3 x}+x (c_4 x+c_3)+c_2 \]