2.6 problem 6

Internal problem ID [3247]

Book: Differential equations for engineers by Wei-Chau XIE, Cambridge Press 2010
Section: Chapter 4. Linear Differential Equations. Page 183
Problem number: 6.
ODE order: 4.
ODE degree: 1.

CAS Maple gives this as type [[_high_order, _missing_x]]

\[ \boxed {y^{\prime \prime \prime \prime }+4 y=0} \]

Solution by Maple

Time used: 0.0 (sec). Leaf size: 33

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

\[ y \left (x \right ) = c_{1} \sin \left (x \right ) {\mathrm e}^{x}+c_{2} {\mathrm e}^{x} \cos \left (x \right )+c_{3} {\mathrm e}^{-x} \sin \left (x \right )+c_{4} {\mathrm e}^{-x} \cos \left (x \right ) \]

Solution by Mathematica

Time used: 0.004 (sec). Leaf size: 40

DSolve[y''''[x]+4*y[x]==0,y[x],x,IncludeSingularSolutions -> True]
                                                                                    
                                                                                    
 

\[ y(x)\to e^{-x} \left (\left (c_4 e^{2 x}+c_1\right ) \cos (x)+\left (c_3 e^{2 x}+c_2\right ) \sin (x)\right ) \]