10.4 problem 4

Internal problem ID [6730]

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: 4.
ODE order: 1.
ODE degree: 1.

Solve \begin {align*} x^{\prime }\left (t \right )&=-\frac {5 x \left (t \right )}{2}+2 y \left (t \right )\\ y^{\prime }\left (t \right )&=\frac {3 x \left (t \right )}{4}-2 y \left (t \right ) \end {align*}

Solution by Maple

Time used: 0.031 (sec). Leaf size: 36

dsolve([diff(x(t),t)=-5/2*x(t)+2*y(t),diff(y(t),t)=3/4*x(t)-2*y(t)],[x(t), y(t)], singsol=all)
 

\[ x \left (t \right ) = \frac {4 c_{1} {\mathrm e}^{-t}}{3}-2 c_{2} {\mathrm e}^{-\frac {7 t}{2}} \] \[ y \left (t \right ) = c_{1} {\mathrm e}^{-t}+c_{2} {\mathrm e}^{-\frac {7 t}{2}} \]

Solution by Mathematica

Time used: 0.012 (sec). Leaf size: 165

DSolve[{x'[t]==5/2*x[t]+2*y[t],y'[t]==3/4*x[t]-2*y[t]},{x[t],y[t]},t,IncludeSingularSolutions -> True]
 

\begin{align*} x(t)\to \frac {1}{210} e^{\frac {1}{4} \left (t-\sqrt {105} t\right )} \left (3 c_1 \left (\left (35+3 \sqrt {105}\right ) e^{\frac {\sqrt {105} t}{2}}+35-3 \sqrt {105}\right )+8 \sqrt {105} c_2 \left (e^{\frac {\sqrt {105} t}{2}}-1\right )\right ) y(t)\to \frac {1}{70} e^{\frac {1}{4} \left (t-\sqrt {105} t\right )} \left (\sqrt {105} c_1 \left (e^{\frac {\sqrt {105} t}{2}}-1\right )-c_2 \left (\left (3 \sqrt {105}-35\right ) e^{\frac {\sqrt {105} t}{2}}-35-3 \sqrt {105}\right )\right ) \end{align*}