72.15.12 problem 23

Internal problem ID [14814]
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 : 23
Date solved : Thursday, March 13, 2025 at 04:19:27 AM
CAS classification : [[_2nd_order, _missing_x]]

\begin{align*} y^{\prime \prime }+5 y^{\prime }+6 y&=0 \end{align*}

With initial conditions

\begin{align*} y \left (0\right )&=0\\ y^{\prime }\left (0\right )&=2 \end{align*}

✓ Maple. Time used: 0.015 (sec). Leaf size: 17

ode:=diff(diff(y(t),t),t)+5*diff(y(t),t)+6*y(t) = 0; 
ic:=y(0) = 0, D(y)(0) = 2; 
dsolve([ode,ic],y(t), singsol=all);
 

\[ y = -2 \,{\mathrm e}^{-3 t}+2 \,{\mathrm e}^{-2 t} \]

✓ Mathematica. Time used: 0.014 (sec). Leaf size: 17

ode=D[y[t],{t,2}]+5*D[y[t],t]+6*y[t]==0; 
ic={y[0]==0,Derivative[1][y][0] ==2}; 
DSolve[{ode,ic},y[t],t,IncludeSingularSolutions->True]
 

\[ y(t)\to 2 e^{-3 t} \left (e^t-1\right ) \]

✓ Sympy. Time used: 0.205 (sec). Leaf size: 14

from sympy import * 
t = symbols("t") 
y = Function("y") 
ode = Eq(6*y(t) + 5*Derivative(y(t), t) + Derivative(y(t), (t, 2)),0) 
ics = {y(0): 0, Subs(Derivative(y(t), t), t, 0): 2} 
dsolve(ode,func=y(t),ics=ics)
 

\[ y{\left (t \right )} = \left (2 - 2 e^{- t}\right ) e^{- 2 t} \]