49.10.1 problem 1(a)

Internal problem ID [7659]
Book : An introduction to Ordinary Differential Equations. Earl A. Coddington. Dover. NY 1961
Section : Chapter 2. Linear equations with constant coefficients. Page 89
Problem number : 1(a)
Date solved : Monday, January 27, 2025 at 03:09:07 PM
CAS classification : [[_3rd_order, _with_linear_symmetries]]

\begin{align*} y^{\prime \prime \prime }-y&=x \end{align*}

Solution by Maple

Time used: 0.003 (sec). Leaf size: 38

dsolve(diff(y(x),x$3)-y(x)=x,y(x), singsol=all)
 
\[ y = -x +{\mathrm e}^{x} c_{1} +c_{2} {\mathrm e}^{-\frac {x}{2}} \cos \left (\frac {\sqrt {3}\, x}{2}\right )+c_3 \,{\mathrm e}^{-\frac {x}{2}} \sin \left (\frac {\sqrt {3}\, x}{2}\right ) \]

Solution by Mathematica

Time used: 0.004 (sec). Leaf size: 57

DSolve[D[y[x],{x,3}]-y[x]==x,y[x],x,IncludeSingularSolutions -> True]
 
\[ y(x)\to -x+c_1 e^x+c_2 e^{-x/2} \cos \left (\frac {\sqrt {3} x}{2}\right )+c_3 e^{-x/2} \sin \left (\frac {\sqrt {3} x}{2}\right ) \]