20.19.1 problem 2

Internal problem ID [3881]
Book : Differential equations and linear algebra, Stephen W. Goode and Scott A Annin. Fourth edition, 2015
Section : Chapter 9, First order linear systems. Section 9.8 (Matrix exponential function), page 642
Problem number : 2
Date solved : Monday, January 27, 2025 at 08:03:50 AM
CAS classification : system_of_ODEs

\begin{align*} \frac {d}{d t}x_{1} \left (t \right )&=2 x_{1} \left (t \right )+x_{2} \left (t \right )\\ \frac {d}{d t}x_{2} \left (t \right )&=2 x_{2} \left (t \right ) \end{align*}

Solution by Maple

Time used: 0.033 (sec). Leaf size: 23

dsolve([diff(x__1(t),t)=2*x__1(t)+x__2(t),diff(x__2(t),t)=2*x__2(t)],singsol=all)
 
\begin{align*} x_{1} \left (t \right ) &= {\mathrm e}^{2 t} \left (c_{2} t +c_{1} \right ) \\ x_{2} \left (t \right ) &= c_{2} {\mathrm e}^{2 t} \\ \end{align*}

Solution by Mathematica

Time used: 0.003 (sec). Leaf size: 29

DSolve[{D[x1[t],t]==2*x1[t]+x2[t],D[x2[t],t]==2*x2[t]},{x1[t],x2[t]},t,IncludeSingularSolutions -> True]
 
\begin{align*} \text {x1}(t)\to e^{2 t} (c_2 t+c_1) \\ \text {x2}(t)\to c_2 e^{2 t} \\ \end{align*}