17.2 problem 2

Internal problem ID [767]

Book: Elementary differential equations and boundary value problems, 10th ed., Boyce and DiPrima
Section: Chapter 7.8, Repeated Eigenvalues. page 436
Problem number: 2.
ODE order: 1.
ODE degree: 1.

Solve \begin {align*} x_{1}^{\prime }\relax (t )&=4 x_{1} \relax (t )-2 x_{2} \relax (t )\\ x_{2}^{\prime }\relax (t )&=8 x_{1} \relax (t )-4 x_{2} \relax (t ) \end {align*}

Solution by Maple

Time used: 0.047 (sec). Leaf size: 24

dsolve([diff(x__1(t),t)=4*x__1(t)-2*x__2(t),diff(x__2(t),t)=8*x__1(t)-4*x__2(t)],[x__1(t), x__2(t)], singsol=all)
 

\[ x_{1} \relax (t ) = \frac {1}{8} c_{1}+\frac {1}{2} t c_{1}+\frac {1}{2} c_{2} \] \[ x_{2} \relax (t ) = t c_{1}+c_{2} \]

Solution by Mathematica

Time used: 0.002 (sec). Leaf size: 34

DSolve[{x1'[t]==4*x1[t]-2*x2[t],x2'[t]==8*x1[t]-4*x2[t]},{x1[t],x2[t]},t,IncludeSingularSolutions -> True]
 

\begin{align*} \text {x1}(t)\to 4 c_1 t-2 c_2 t+c_1 \\ \text {x2}(t)\to 8 c_1 t-4 c_2 t+c_2 \\ \end{align*}