6.3 problem Problem 4(c)

Internal problem ID [12371]

Book: APPLIED DIFFERENTIAL EQUATIONS The Primary Course by Vladimir A. Dobrushkin. CRC Press 2015
Section: Chapter 6.4 Reduction to a single ODE. Problems page 415
Problem number: Problem 4(c).
ODE order: 1.
ODE degree: 1.

Solve \begin {align*} x^{\prime }\left (t \right )&=\frac {6}{5}+\frac {3 y}{5}-\frac {3 t}{5}+x \left (t \right )\\ y^{\prime }&=\frac {6}{5}-\frac {2 y}{5}+\frac {2 t}{5} \end {align*}

Solution by Maple

Time used: 0.031 (sec). Leaf size: 30

dsolve([diff(x(t),t)-diff(y(t),t)=x(t)+y(t)-t,2*diff(x(t),t)+3*diff(y(t),t)=2*x(t)+6],singsol=all)
 

\begin{align*} x \left (t \right ) &= c_{2} {\mathrm e}^{t}+{\mathrm e}^{-\frac {2 t}{5}} c_{1} -\frac {3}{2} \\ y \left (t \right ) &= -\frac {7 \,{\mathrm e}^{-\frac {2 t}{5}} c_{1}}{3}+\frac {1}{2}+t \\ \end{align*}

Solution by Mathematica

Time used: 0.438 (sec). Leaf size: 53

DSolve[{x'[t]-y'[t]==x[t]+y[t]-t,2*x'[t]+3*y'[t]==2*x[t]+6},{x[t],y[t]},t,IncludeSingularSolutions -> True]
 

\begin{align*} x(t)\to \left (c_1+\frac {3 c_2}{7}\right ) e^t-\frac {3}{7} c_2 e^{-2 t/5}-\frac {3}{2} \\ y(t)\to t+c_2 e^{-2 t/5}+\frac {1}{2} \\ \end{align*}