76.13.26 problem 26

Internal problem ID [17537]
Book : Differential equations. An introduction to modern methods and applications. James Brannan, William E. Boyce. Third edition. Wiley 2015
Section : Chapter 4. Second order linear equations. Section 4.3 (Linear homogeneous equations with constant coefficients). Problems at page 239
Problem number : 26
Date solved : Monday, March 31, 2025 at 04:16:47 PM
CAS classification : [[_2nd_order, _missing_x]]

\begin{align*} y^{\prime \prime }+4 y^{\prime }+\frac {25 y}{4}&=0 \end{align*}

✓ Maple. Time used: 0.002 (sec). Leaf size: 22

ode:=diff(diff(y(x),x),x)+4*diff(y(x),x)+25/4*y(x) = 0; 
dsolve(ode,y(x), singsol=all);
 

\[ y = {\mathrm e}^{-2 x} \left (c_1 \sin \left (\frac {3 x}{2}\right )+c_2 \cos \left (\frac {3 x}{2}\right )\right ) \]

✓ Mathematica. Time used: 0.015 (sec). Leaf size: 30

ode=D[y[x],{x,2}]+4*D[y[x],x]+625/100*y[x]==0; 
ic={}; 
DSolve[{ode,ic},y[x],x,IncludeSingularSolutions->True]
 

\[ y(x)\to e^{-2 x} \left (c_2 \cos \left (\frac {3 x}{2}\right )+c_1 \sin \left (\frac {3 x}{2}\right )\right ) \]

✓ Sympy. Time used: 0.156 (sec). Leaf size: 24

from sympy import * 
x = symbols("x") 
y = Function("y") 
ode = Eq(25*y(x)/4 + 4*Derivative(y(x), x) + Derivative(y(x), (x, 2)),0) 
ics = {} 
dsolve(ode,func=y(x),ics=ics)
 

\[ y{\left (x \right )} = \left (C_{1} \sin {\left (\frac {3 x}{2} \right )} + C_{2} \cos {\left (\frac {3 x}{2} \right )}\right ) e^{- 2 x} \]