66.15.1 problem 3

Internal problem ID [16168]
Book : DIFFERENTIAL EQUATIONS by Paul Blanchard, Robert L. Devaney, Glen R. Hall. 4th edition. Brooks/Cole. Boston, USA. 2012
Section : Chapter 3. Linear Systems. Review Exercises for chapter 3. page 376
Problem number : 3
Date solved : Thursday, October 02, 2025 at 10:43:10 AM
CAS classification : system_of_ODEs

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

✓ Maple. Time used: 0.117 (sec). Leaf size: 19

ode:=[diff(x(t),t) = 3*x(t), diff(y(t),t) = -2*y(t)]; 
dsolve(ode);
 

\begin{align*} x \left (t \right ) &= c_2 \,{\mathrm e}^{3 t} \\ y \left (t \right ) &= c_1 \,{\mathrm e}^{-2 t} \\ \end{align*}

✓ Mathematica. Time used: 0.033 (sec). Leaf size: 65

ode={D[x[t],t]==3*x[t]+0*y[t],D[y[t],t]==0*x[t]-2*y[t]}; 
ic={}; 
DSolve[{ode,ic},{x[t],y[t]},t,IncludeSingularSolutions->True]
 

\begin{align*} x(t)&\to c_1 e^{3 t}\\ y(t)&\to c_2 e^{-2 t}\\ x(t)&\to c_1 e^{3 t}\\ y(t)&\to 0\\ x(t)&\to 0\\ y(t)&\to c_2 e^{-2 t}\\ x(t)&\to 0\\ y(t)&\to 0 \end{align*}

✓ Sympy. Time used: 0.033 (sec). Leaf size: 17

from sympy import * 
t = symbols("t") 
x = Function("x") 
y = Function("y") 
ode=[Eq(-3*x(t) + Derivative(x(t), t),0),Eq(2*y(t) + Derivative(y(t), t),0)] 
ics = {} 
dsolve(ode,func=[x(t),y(t)],ics=ics)
 

\[ \left [ x{\left (t \right )} = C_{1} e^{3 t}, \ y{\left (t \right )} = C_{2} e^{- 2 t}\right ] \]