10.28 problem 29

Internal problem ID [6001]

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 8.2. Page 346
Problem number: 29.
ODE order: 1.
ODE degree: 1.

Solve \begin {align*} x^{\prime }\relax (t )&=2 x \relax (t )+4 y \relax (t )\\ y^{\prime }\relax (t )&=-x \relax (t )+6 y \relax (t ) \end {align*}

With initial conditions \[ [x \relax (0) = -1, y \relax (0) = 6] \]

Solution by Maple

Time used: 0.054 (sec). Leaf size: 28

dsolve([diff(x(t),t) = 2*x(t)+4*y(t), diff(y(t),t) = -x(t)+6*y(t), x(0) = -1, y(0) = 6],[x(t), y(t)], singsol=all)
 

\[ x \relax (t ) = {\mathrm e}^{4 t} \left (26 t -1\right ) \] \[ y \relax (t ) = {\mathrm e}^{4 t} \left (13 t +6\right ) \]

Solution by Mathematica

Time used: 0.003 (sec). Leaf size: 30

DSolve[{x'[t]==2*x[t]+4*y[t],y'[t]==-x[t]+6*y[t]},{x[0]==-1,y[0]==6},{x[t],y[t]},t,IncludeSingularSolutions -> True]
 

\begin{align*} x(t)\to e^{4 t} (26 t-1) \\ y(t)\to e^{4 t} (13 t+6) \\ \end{align*}