52.9.10 problem 10
Internal
problem
ID
[8388]
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
8.1.
Page
332
Problem
number
:
10
Date
solved
:
Sunday, March 30, 2025 at 01:00:29 PM
CAS
classification
:
system_of_ODEs
\begin{align*} \frac {d}{d t}x \left (t \right )&=3 x \left (t \right )-7 y \left (t \right )+4 \sin \left (t \right )+\left (t -4\right ) {\mathrm e}^{4 t}\\ \frac {d}{d t}y \left (t \right )&=x \left (t \right )+y \left (t \right )+8 \sin \left (t \right )+\left (2 t +1\right ) {\mathrm e}^{4 t} \end{align*}
✓ Maple. Time used: 1.405 (sec). Leaf size: 133
ode:=[diff(x(t),t) = 3*x(t)-7*y(t)+4*sin(t)+(t-4)*exp(4*t), diff(y(t),t) = x(t)+y(t)+8*sin(t)+(2*t+1)*exp(4*t)];
dsolve(ode);
\begin{align*}
x \left (t \right ) &= {\mathrm e}^{2 t} \sin \left (\sqrt {6}\, t \right ) c_2 +{\mathrm e}^{2 t} \cos \left (\sqrt {6}\, t \right ) c_1 -\frac {11 \,{\mathrm e}^{4 t} t}{10}-\frac {34 \,{\mathrm e}^{4 t}}{25}-\frac {204 \cos \left (t \right )}{97}-\frac {556 \sin \left (t \right )}{97} \\
y \left (t \right ) &= \frac {3 \,{\mathrm e}^{4 t} t}{10}-\frac {11 \,{\mathrm e}^{4 t}}{50}+\frac {{\mathrm e}^{2 t} \sqrt {6}\, \sin \left (\sqrt {6}\, t \right ) c_1}{7}-\frac {{\mathrm e}^{2 t} \sqrt {6}\, \cos \left (\sqrt {6}\, t \right ) c_2}{7}+\frac {{\mathrm e}^{2 t} \sin \left (\sqrt {6}\, t \right ) c_2}{7}+\frac {{\mathrm e}^{2 t} \cos \left (\sqrt {6}\, t \right ) c_1}{7}-\frac {8 \cos \left (t \right )}{97}-\frac {212 \sin \left (t \right )}{97} \\
\end{align*}
✓ Mathematica. Time used: 4.715 (sec). Leaf size: 190
ode={D[x[t],t]==3*x[t]-7*y[t]+4*Sin[t]+(t-4)*Exp[4*t],D[y[t],t]==x[t]+y[t]+8*Sin[t]+(2*t+1)*Exp[4*t]};
ic={};
DSolve[{ode,ic},{x[t],y[t]},t,IncludeSingularSolutions->True]
\begin{align*}
x(t)\to -\frac {11}{10} e^{4 t} t-\frac {34 e^{4 t}}{25}-\frac {556 \sin (t)}{97}-\frac {204 \cos (t)}{97}+c_1 e^{2 t} \cos \left (\sqrt {6} t\right )+\frac {c_1 e^{2 t} \sin \left (\sqrt {6} t\right )}{\sqrt {6}}-\frac {7 c_2 e^{2 t} \sin \left (\sqrt {6} t\right )}{\sqrt {6}} \\
y(t)\to \frac {3}{10} e^{4 t} t-\frac {11 e^{4 t}}{50}-\frac {212 \sin (t)}{97}-\frac {8 \cos (t)}{97}+c_2 e^{2 t} \cos \left (\sqrt {6} t\right )+\frac {c_1 e^{2 t} \sin \left (\sqrt {6} t\right )}{\sqrt {6}}-\frac {c_2 e^{2 t} \sin \left (\sqrt {6} t\right )}{\sqrt {6}} \\
\end{align*}
✓ Sympy. Time used: 2.774 (sec). Leaf size: 372
from sympy import *
t = symbols("t")
x = Function("x")
y = Function("y")
ode=[Eq((4 - t)*exp(4*t) - 3*x(t) + 7*y(t) - 4*sin(t) + Derivative(x(t), t),0),Eq((-2*t - 1)*exp(4*t) - x(t) - y(t) - 8*sin(t) + Derivative(y(t), t),0)]
ics = {}
dsolve(ode,func=[x(t),y(t)],ics=ics)
\[
\left [ x{\left (t \right )} = - \frac {11 t e^{4 t} \sin ^{2}{\left (\sqrt {6} t \right )}}{10} - \frac {11 t e^{4 t} \cos ^{2}{\left (\sqrt {6} t \right )}}{10} - \left (C_{1} + \sqrt {6} C_{2}\right ) e^{2 t} \sin {\left (\sqrt {6} t \right )} - \left (\sqrt {6} C_{1} - C_{2}\right ) e^{2 t} \cos {\left (\sqrt {6} t \right )} - \frac {34 e^{4 t} \sin ^{2}{\left (\sqrt {6} t \right )}}{25} - \frac {34 e^{4 t} \cos ^{2}{\left (\sqrt {6} t \right )}}{25} - \frac {556 \sin {\left (t \right )} \sin ^{2}{\left (\sqrt {6} t \right )}}{97} - \frac {556 \sin {\left (t \right )} \cos ^{2}{\left (\sqrt {6} t \right )}}{97} - \frac {204 \sin ^{2}{\left (\sqrt {6} t \right )} \cos {\left (t \right )}}{97} - \frac {204 \cos {\left (t \right )} \cos ^{2}{\left (\sqrt {6} t \right )}}{97}, \ y{\left (t \right )} = - C_{1} e^{2 t} \sin {\left (\sqrt {6} t \right )} + C_{2} e^{2 t} \cos {\left (\sqrt {6} t \right )} + \frac {3 t e^{4 t} \sin ^{2}{\left (\sqrt {6} t \right )}}{10} + \frac {3 t e^{4 t} \cos ^{2}{\left (\sqrt {6} t \right )}}{10} - \frac {11 e^{4 t} \sin ^{2}{\left (\sqrt {6} t \right )}}{50} - \frac {11 e^{4 t} \cos ^{2}{\left (\sqrt {6} t \right )}}{50} - \frac {212 \sin {\left (t \right )} \sin ^{2}{\left (\sqrt {6} t \right )}}{97} - \frac {212 \sin {\left (t \right )} \cos ^{2}{\left (\sqrt {6} t \right )}}{97} - \frac {8 \sin ^{2}{\left (\sqrt {6} t \right )} \cos {\left (t \right )}}{97} - \frac {8 \cos {\left (t \right )} \cos ^{2}{\left (\sqrt {6} t \right )}}{97}\right ]
\]