23.3 problem section 10.6, problem 3

Internal problem ID [1638]

Book: Elementary differential equations with boundary value problems. William F. Trench. Brooks/Cole 2001
Section: Chapter 10 Linear system of Differential equations. Section 10.6, constant coefficient homogeneous system III. Page 566
Problem number: section 10.6, problem 3.
ODE order: 1.
ODE degree: 1.

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

Solution by Maple

Time used: 0.016 (sec). Leaf size: 57

dsolve([diff(y__1(t),t)=1*y__1(t)+2*y__2(t),diff(y__2(t),t)=-4*y__1(t)+5*y__2(t)],singsol=all)
 

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

Solution by Mathematica

Time used: 0.006 (sec). Leaf size: 60

DSolve[{y1'[t]==1*y1[t]+2*y2[t],y2'[t]==-4*y1[t]+5*y2[t]},{y1[t],y2[t]},t,IncludeSingularSolutions -> True]
                                                                                    
                                                                                    
 

\begin{align*} \text {y1}(t)\to e^{3 t} (c_1 \cos (2 t)+(c_2-c_1) \sin (2 t)) \\ \text {y2}(t)\to e^{3 t} (c_2 \cos (2 t)+(c_2-2 c_1) \sin (2 t)) \\ \end{align*}