7.15 problem Exercise 20.16, page 220

Internal problem ID [4078]

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 20.16, page 220.
ODE order: 3.
ODE degree: 1.

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

Solve \begin {gather*} \boxed {y^{\prime \prime \prime }-6 y^{\prime \prime }+12 y^{\prime }-8 y=0} \end {gather*}

Solution by Maple

Time used: 0.016 (sec). Leaf size: 27

dsolve(diff(y(x),x$3)-6*diff(y(x),x$2)+12*diff(y(x),x)-8*y(x)=0,y(x), singsol=all)
 

\[ y \relax (x ) = {\mathrm e}^{2 x} c_{1}+c_{2} {\mathrm e}^{2 x} x +c_{3} {\mathrm e}^{2 x} x^{2} \]

Solution by Mathematica

Time used: 0.004 (sec). Leaf size: 23

DSolve[y'''[x]-6*y''[x]+12*y'[x]-8*y[x]==0,y[x],x,IncludeSingularSolutions -> True]
 

\begin{align*} y(x)\to e^{2 x} (x (c_3 x+c_2)+c_1) \\ \end{align*}