81.4.5 problem 5

Internal problem ID [18659]
Book : A short course on differential equations. By Donald Francis Campbell. Maxmillan company. London. 1907
Section : Chapter IV. Ordinary linear differential equations with constant coefficients. Exercises at page 48
Problem number : 5
Date solved : Tuesday, January 28, 2025 at 12:08:57 PM
CAS classification : [[_3rd_order, _missing_x]]

\begin{align*} y^{\prime \prime \prime }-3 y^{\prime \prime }+3 y^{\prime }-y&=0 \end{align*}

Solution by Maple

Time used: 0.002 (sec). Leaf size: 17

dsolve(diff(y(x),x$3)-3*diff(y(x),x$2)+3*diff(y(x),x)-y(x)=0,y(x), singsol=all)
 
\[ y \left (x \right ) = {\mathrm e}^{x} \left (c_3 \,x^{2}+c_{2} x +c_{1} \right ) \]

Solution by Mathematica

Time used: 0.003 (sec). Leaf size: 21

DSolve[D[y[x],{x,3}]-3*D[y[x],{x,2}]+3*D[y[x],x]-y[x]==0,y[x],x,IncludeSingularSolutions -> True]
 
\[ y(x)\to e^x (x (c_3 x+c_2)+c_1) \]