13.9.4 problem 4

Internal problem ID [2390]
Book : Differential equations and their applications, 3rd ed., M. Braun
Section : Section 2.2.2, Equal roots, reduction of order. Page 147
Problem number : 4
Date solved : Sunday, March 30, 2025 at 12:00:06 AM
CAS classification : [[_2nd_order, _missing_x]]

\begin{align*} 4 y^{\prime \prime }-4 y^{\prime }+y&=0 \end{align*}

With initial conditions

\begin{align*} y \left (0\right )&=0\\ y^{\prime }\left (0\right )&=3 \end{align*}

✓ Maple. Time used: 0.044 (sec). Leaf size: 11

ode:=4*diff(diff(y(t),t),t)-4*diff(y(t),t)+y(t) = 0; 
ic:=y(0) = 0, D(y)(0) = 3; 
dsolve([ode,ic],y(t), singsol=all);
 

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

✓ Mathematica. Time used: 0.018 (sec). Leaf size: 15

ode=4*D[y[t],{t,2}]-4*D[y[t],t]+y[t]==0; 
ic={y[0]==0,Derivative[1][y][0] ==3}; 
DSolve[{ode,ic},y[t],t,IncludeSingularSolutions->True]
 

\[ y(t)\to 3 e^{t/2} t \]

✓ Sympy. Time used: 0.185 (sec). Leaf size: 10

from sympy import * 
t = symbols("t") 
y = Function("y") 
ode = Eq(y(t) - 4*Derivative(y(t), t) + 4*Derivative(y(t), (t, 2)),0) 
ics = {y(0): 0, Subs(Derivative(y(t), t), t, 0): 3} 
dsolve(ode,func=y(t),ics=ics)
 

\[ y{\left (t \right )} = 3 t e^{\frac {t}{2}} \]