10.32 problem 35

Internal problem ID [6004]

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: 35.
ODE order: 1.
ODE degree: 1.

Solve \begin {align*} x^{\prime }\left (t \right )&=5 x \left (t \right )+y \left (t \right )\\ y^{\prime }\left (t \right )&=-2 x \left (t \right )+3 y \left (t \right ) \end {align*}

Solution by Maple

Time used: 0.015 (sec). Leaf size: 46

dsolve([diff(x(t),t)=5*x(t)+y(t),diff(y(t),t)=-2*x(t)+3*y(t)],[x(t), y(t)], singsol=all)
 

\[ x \left (t \right ) = -\frac {{\mathrm e}^{4 t} \left (\cos \left (t \right ) c_{1} +c_{2} \cos \left (t \right )+c_{1} \sin \left (t \right )-\sin \left (t \right ) c_{2} \right )}{2} \] \[ y \left (t \right ) = {\mathrm e}^{4 t} \left (c_{2} \cos \left (t \right )+c_{1} \sin \left (t \right )\right ) \]

Solution by Mathematica

Time used: 0.005 (sec). Leaf size: 51

DSolve[{x'[t]==5*x[t]+y[t],y'[t]==-2*x[t]+3*y[t]},{x[t],y[t]},t,IncludeSingularSolutions -> True]
 

\begin{align*} x(t)\to e^{4 t} (c_1 \cos (t)+(c_1+c_2) \sin (t)) \\ y(t)\to e^{4 t} (c_2 \cos (t)-(2 c_1+c_2) \sin (t)) \\ \end{align*}