90.12.6 problem 6

Internal problem ID [25208]
Book : Ordinary Differential Equations. By William Adkins and Mark G Davidson. Springer. NY. 2010. ISBN 978-1-4614-3617-1
Section : Chapter 3. Second Order Constant Coefficient Linear Differential Equations. Exercises at page 213
Problem number : 6
Date solved : Thursday, October 02, 2025 at 11:58:58 PM
CAS classification : [[_2nd_order, _with_linear_symmetries]]

\begin{align*} y^{\prime \prime }+2 y^{\prime }+3 y&={\mathrm e}^{-t} \end{align*}

✓ Maple. Time used: 0.002 (sec). Leaf size: 27

ode:=diff(diff(y(t),t),t)+2*diff(y(t),t)+3*y(t) = exp(-t); 
dsolve(ode,y(t), singsol=all);
 

\[ y = {\mathrm e}^{-t} \left (\frac {1}{2}+c_2 \sin \left (\sqrt {2}\, t \right )+c_1 \cos \left (\sqrt {2}\, t \right )\right ) \]

✓ Mathematica. Time used: 0.048 (sec). Leaf size: 40

ode=D[y[t],{t,2}]+2*D[y[t],t]+3*y[t]==Exp[-t]; 
ic={}; 
DSolve[{ode,ic},y[t],t,IncludeSingularSolutions->True]
 

\begin{align*} y(t)&\to \frac {1}{2} e^{-t} \left (2 c_2 \cos \left (\sqrt {2} t\right )+2 c_1 \sin \left (\sqrt {2} t\right )+1\right ) \end{align*}

✓ Sympy. Time used: 0.136 (sec). Leaf size: 29

from sympy import * 
t = symbols("t") 
y = Function("y") 
ode = Eq(3*y(t) + 2*Derivative(y(t), t) + Derivative(y(t), (t, 2)) - exp(-t),0) 
ics = {} 
dsolve(ode,func=y(t),ics=ics)
 

\[ y{\left (t \right )} = \left (C_{1} \sin {\left (\sqrt {2} t \right )} + C_{2} \cos {\left (\sqrt {2} t \right )} + \frac {1}{2}\right ) e^{- t} \]