14.19 problem 19

Internal problem ID [2220]

Book: Differential Equations by Alfred L. Nelson, Karl W. Folley, Max Coral. 3rd ed. DC heath. Boston. 1964
Section: Exercise 23, page 106
Problem number: 19.
ODE order: 3.
ODE degree: 1.

CAS Maple gives this as type [[_3rd_order, _with_linear_symmetries]]

\[ \boxed {y^{\prime \prime \prime }-y=x^{2}} \]

Solution by Maple

Time used: 0.0 (sec). Leaf size: 40

dsolve(diff(y(x),x$3)-y(x)=x^2,y(x), singsol=all)
 

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

Solution by Mathematica

Time used: 0.003 (sec). Leaf size: 59

DSolve[y'''[x]-y[x]==x^2,y[x],x,IncludeSingularSolutions -> True]
 

\[ y(x)\to -x^2+c_1 e^x+c_2 e^{-x/2} \cos \left (\frac {\sqrt {3} x}{2}\right )+c_3 e^{-x/2} \sin \left (\frac {\sqrt {3} x}{2}\right ) \]