19.3 problem 3

Internal problem ID [794]

Book: Elementary differential equations and boundary value problems, 10th ed., Boyce and DiPrima
Section: Chapter 9.1, The Phase Plane: Linear Systems. page 505
Problem number: 3.
ODE order: 1.
ODE degree: 1.

Solve \begin {align*} x_{1}^{\prime }\relax (t )&=2 x_{1}\relax (t )-x_{2}\relax (t )\\ x_{2}^{\prime }\relax (t )&=3 x_{1}\relax (t )-2 x_{2}\relax (t ) \end {align*}

Solution by Maple

Time used: 0.018 (sec). Leaf size: 31

dsolve([diff(x__1(t),t)=2*x__1(t)-1*x__2(t),diff(x__2(t),t)=3*x__1(t)-2*x__2(t)],[x__1(t), x__2(t)], singsol=all)
 

\[ x_{1}\relax (t ) = \frac {{\mathrm e}^{-t} c_{1}}{3}+c_{2} {\mathrm e}^{t} \] \[ x_{2}\relax (t ) = {\mathrm e}^{-t} c_{1}+c_{2} {\mathrm e}^{t} \]

Solution by Mathematica

Time used: 0.003 (sec). Leaf size: 43

DSolve[{x1'[t]==2*x1[t]-1*x2[t],x2'[t]==3*x1[t]-2*x2[t]},{x1[t],x2[t]},t,IncludeSingularSolutions -> True]
 

\begin{align*} \text {x1}(t)\to c_1 \cosh (t)+(2 c_1-c_2) \sinh (t) \\ \text {x2}(t)\to 3 c_1 \sinh (t)+c_2 (\cosh (t)-2 \sinh (t)) \\ \end{align*}