49.7.6 problem 4(g)

Internal problem ID [7645]
Book : An introduction to Ordinary Differential Equations. Earl A. Coddington. Dover. NY 1961
Section : Chapter 2. Linear equations with constant coefficients. Page 74
Problem number : 4(g)
Date solved : Monday, January 27, 2025 at 03:08:56 PM
CAS classification : [[_high_order, _missing_x]]

\begin{align*} y^{\prime \prime \prime \prime }-16 y&=0 \end{align*}

Solution by Maple

Time used: 0.003 (sec). Leaf size: 29

dsolve(diff(y(x),x$4)-16*y(x)=0,y(x), singsol=all)
 
\[ y = {\mathrm e}^{2 x} c_{1} +c_{2} {\mathrm e}^{-2 x}+c_3 \sin \left (2 x \right )+c_4 \cos \left (2 x \right ) \]

Solution by Mathematica

Time used: 0.003 (sec). Leaf size: 36

DSolve[D[y[x],{x,4}]-16*y[x]==0,y[x],x,IncludeSingularSolutions -> True]
 
\[ y(x)\to c_1 e^{2 x}+c_3 e^{-2 x}+c_2 \cos (2 x)+c_4 \sin (2 x) \]