9.14 problem 14

Internal problem ID [6724]

Book: DIFFERENTIAL EQUATIONS with Boundary Value Problems. DENNIS G. ZILL, WARREN S. WRIGHT, MICHAEL R. CULLEN. Brooks/Cole. Boston, MA. 2013. 8th edition.
Section: CHAPTER 8 SYSTEMS OF LINEAR FIRST-ORDER DIFFERENTIAL EQUATIONS. EXERCISES 8.1. Page 332
Problem number: 14.
ODE order: 1.
ODE degree: 1.

Solve \begin {align*} x^{\prime }\left (t \right )&=2 x \left (t \right )+y \left (t \right )\\ y^{\prime }\left (t \right )&=-x \left (t \right ) \end {align*}

Solution by Maple

Time used: 0.031 (sec). Leaf size: 26

dsolve([diff(x(t),t)=2*x(t)+y(t),diff(y(t),t)=-x(t)],[x(t), y(t)], singsol=all)
 

\[ x \left (t \right ) = -{\mathrm e}^{t} \left (c_{2} t +c_{1} +c_{2} \right ) \] \[ y \left (t \right ) = {\mathrm e}^{t} \left (c_{2} t +c_{1} \right ) \]

Solution by Mathematica

Time used: 0.002 (sec). Leaf size: 38

DSolve[{x'[t]==2*x[t]+y[t],y'[t]==-x[t]},{x[t],y[t]},t,IncludeSingularSolutions -> True]
 

\begin{align*} x(t)\to e^t (c_1 (t+1)+c_2 t) y(t)\to e^t (c_2-(c_1+c_2) t) \end{align*}