29.5.3 problem 3

Internal problem ID [7272]
Book : Mathematical Methods in the Physical Sciences. third edition. Mary L. Boas. John Wiley. 2006
Section : Chapter 8, Ordinary differential equations. Section 5. SECOND-ORDER LINEAR EQUATIONSWITH CONSTANT COEFFICIENTS AND ZERO RIGHT-HAND SIDE. page 414
Problem number : 3
Date solved : Tuesday, September 30, 2025 at 04:27:39 PM
CAS classification : [[_2nd_order, _missing_x]]

\begin{align*} y^{\prime \prime }+9 y^{\prime }&=0 \end{align*}
Maple. Time used: 0.002 (sec). Leaf size: 12
ode:=diff(diff(y(x),x),x)+9*diff(y(x),x) = 0; 
dsolve(ode,y(x), singsol=all);
 
\[ y = c_1 +c_2 \,{\mathrm e}^{-9 x} \]
Mathematica. Time used: 0.014 (sec). Leaf size: 19
ode=D[y[x],{x,2}]+9*D[y[x],x]==0; 
ic={}; 
DSolve[{ode,ic},y[x],x,IncludeSingularSolutions->True]
 
\begin{align*} y(x)&\to c_2-\frac {1}{9} c_1 e^{-9 x} \end{align*}
Sympy. Time used: 0.077 (sec). Leaf size: 10
from sympy import * 
x = symbols("x") 
y = Function("y") 
ode = Eq(9*Derivative(y(x), x) + Derivative(y(x), (x, 2)),0) 
ics = {} 
dsolve(ode,func=y(x),ics=ics)
 
\[ y{\left (x \right )} = C_{1} + C_{2} e^{- 9 x} \]