Internal problem ID [6763]
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: 40.
ODE order: 1.
ODE degree: 1.
Solve \begin {align*} x^{\prime }\left (t \right )&=2 x \left (t \right )+y \left (t \right )+2 z \left (t \right )\\ y^{\prime }\left (t \right )&=3 x \left (t \right )+6 z \left (t \right )\\ z^{\prime }\left (t \right )&=-4 x \left (t \right )-3 z \left (t \right ) \end {align*}
✓ Solution by Maple
Time used: 0.078 (sec). Leaf size: 92
dsolve([diff(x(t),t)=2*x(t)+y(t)+2*z(t),diff(y(t),t)=3*x(t)+6*z(t),diff(z(t),t)=-4*x(t)-3*z(t)],[x(t), y(t), z(t)], singsol=all)
\[ x \left (t \right ) = -\frac {{\mathrm e}^{t} \left (2 \sin \left (2 t \right ) c_{2} -\sin \left (2 t \right ) c_{3} +\cos \left (2 t \right ) c_{2} +2 \cos \left (2 t \right ) c_{3} \right )}{2} \] \[ y \left (t \right ) = -2 c_{1} {\mathrm e}^{-3 t}-\frac {3 c_{2} {\mathrm e}^{t} \cos \left (2 t \right )}{2}+\frac {3 c_{3} {\mathrm e}^{t} \sin \left (2 t \right )}{2} \] \[ z \left (t \right ) = c_{1} {\mathrm e}^{-3 t}+c_{2} {\mathrm e}^{t} \sin \left (2 t \right )+c_{3} {\mathrm e}^{t} \cos \left (2 t \right ) \]
✓ Solution by Mathematica
Time used: 0.016 (sec). Leaf size: 176
DSolve[{x'[t]==2*x[t]+y[t]+2*z[t],y'[t]==3*x[t]+6*z[t],z'[t]==-4*x[t]-3*z[t]},{x[t],y[t],z[t]},t,IncludeSingularSolutions -> True]
\begin{align*} x(t)\to \frac {1}{2} e^t (2 c_1 \cos (2 t)+(c_1+c_2+2 c_3) \sin (2 t)) y(t)\to \frac {2}{5} (-3 c_1+c_2-3 c_3) e^{-3 t}+\frac {3}{5} (2 c_1+c_2+2 c_3) e^t \cos (2 t)-\frac {3}{5} (3 c_1-c_2-2 c_3) e^t \sin (t) \cos (t) z(t)\to \frac {1}{5} e^{-3 t} \left (-(3 c_1-c_2-2 c_3) e^{4 t} \cos (2 t)-2 (2 c_1+c_2+2 c_3) e^{4 t} \sin (2 t)+3 c_1-c_2+3 c_3\right ) \end{align*}