21.3 problem section 10.4, problem 3

Internal problem ID [1591]

Book: Elementary differential equations with boundary value problems. William F. Trench. Brooks/Cole 2001
Section: Chapter 10 Linear system of Differential equations. Section 10.4, constant coefficient homogeneous system. Page 540
Problem number: section 10.4, problem 3.
ODE order: 1.
ODE degree: 1.

Solve \begin {align*} y_{1}^{\prime }\left (t \right )&=-\frac {4 y_{1} \left (t \right )}{5}+\frac {3 y_{2} \left (t \right )}{5}\\ y_{2}^{\prime }\left (t \right )&=-\frac {2 y_{1} \left (t \right )}{5}-\frac {11 y_{2} \left (t \right )}{5} \end {align*}

Solution by Maple

Time used: 0.016 (sec). Leaf size: 36

dsolve([diff(y__1(t),t)=-4/5*y__1(t)+3/5*y__2(t),diff(y__2(t),t)=-2/5*y__1(t)-11/5*y__2(t)],singsol=all)
 

\begin{align*} y_{1} \left (t \right ) &= {\mathrm e}^{-t} c_{1} +c_{2} {\mathrm e}^{-2 t} \\ y_{2} \left (t \right ) &= -\frac {{\mathrm e}^{-t} c_{1}}{3}-2 c_{2} {\mathrm e}^{-2 t} \\ \end{align*}

Solution by Mathematica

Time used: 0.003 (sec). Leaf size: 65

DSolve[{y1'[t]==-4/5*y1[t]+3/5*y2[t],y2'[t]==-2/5*y1[t]-11/5*y2[t]},{y1[t],y2[t]},t,IncludeSingularSolutions -> True]
                                                                                    
                                                                                    
 

\begin{align*} \text {y1}(t)\to \frac {1}{5} e^{-2 t} \left (c_1 \left (6 e^t-1\right )+3 c_2 \left (e^t-1\right )\right ) \\ \text {y2}(t)\to \frac {1}{5} e^{-2 t} \left (-2 c_1 \left (e^t-1\right )-c_2 \left (e^t-6\right )\right ) \\ \end{align*}