10.19.11 problem 11

Internal problem ID [1452]
Book : Elementary differential equations and boundary value problems, 10th ed., Boyce and DiPrima
Section : Chapter 9.1, The Phase Plane: Linear Systems. page 505
Problem number : 11
Date solved : Monday, January 27, 2025 at 04:57:32 AM
CAS classification : system_of_ODEs

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

Solution by Maple

Time used: 0.012 (sec). Leaf size: 19

dsolve([diff(x__1(t),t)=-1*x__1(t)-0*x__2(t),diff(x__2(t),t)=0*x__1(t)-1*x__2(t)],singsol=all)
 
\begin{align*} x_{1} \left (t \right ) &= c_2 \,{\mathrm e}^{-t} \\ x_{2} \left (t \right ) &= {\mathrm e}^{-t} c_1 \\ \end{align*}

Solution by Mathematica

Time used: 0.035 (sec). Leaf size: 65

DSolve[{D[ x1[t],t]==-1*x1[t]-0*x2[t],D[ x2[t],t]==0*x1[t]-1*x2[t]},{x1[t],x2[t]},t,IncludeSingularSolutions -> True]
 
\begin{align*} \text {x1}(t)\to c_1 e^{-t} \\ \text {x2}(t)\to c_2 e^{-t} \\ \text {x1}(t)\to c_1 e^{-t} \\ \text {x2}(t)\to 0 \\ \text {x1}(t)\to 0 \\ \text {x2}(t)\to c_2 e^{-t} \\ \text {x1}(t)\to 0 \\ \text {x2}(t)\to 0 \\ \end{align*}