74.9.24 problem 35

Internal problem ID [16121]
Book : INTRODUCTORY DIFFERENTIAL EQUATIONS. Martha L. Abell, James P. Braselton. Fourth edition 2014. ElScAe. 2014
Section : Chapter 4. Higher Order Equations. Exercises 4.1, page 141
Problem number : 35
Date solved : Thursday, March 13, 2025 at 07:52:17 AM
CAS classification : [[_2nd_order, _missing_x]]

\begin{align*} a y^{\prime \prime }+b y^{\prime }+c y&=0 \end{align*}

✓ Maple. Time used: 0.003 (sec). Leaf size: 49

ode:=a*diff(diff(y(t),t),t)+b*diff(y(t),t)+c*y(t) = 0; 
dsolve(ode,y(t), singsol=all);
 

\[ y = c_{1} {\mathrm e}^{\frac {\left (-b +\sqrt {-4 a c +b^{2}}\right ) t}{2 a}}+c_{2} {\mathrm e}^{-\frac {\left (b +\sqrt {-4 a c +b^{2}}\right ) t}{2 a}} \]

✓ Mathematica. Time used: 0.037 (sec). Leaf size: 55

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

\[ y(t)\to e^{-\frac {t \left (\sqrt {b^2-4 a c}+b\right )}{2 a}} \left (c_2 e^{\frac {t \sqrt {b^2-4 a c}}{a}}+c_1\right ) \]

✓ Sympy. Time used: 0.256 (sec). Leaf size: 46

from sympy import * 
t = symbols("t") 
a = symbols("a") 
b = symbols("b") 
c = symbols("c") 
y = Function("y") 
ode = Eq(a*Derivative(y(t), (t, 2)) + b*Derivative(y(t), t) + c*y(t),0) 
ics = {} 
dsolve(ode,func=y(t),ics=ics)
 

\[ y{\left (t \right )} = C_{1} e^{\frac {t \left (- b + \sqrt {- 4 a c + b^{2}}\right )}{2 a}} + C_{2} e^{- \frac {t \left (b + \sqrt {- 4 a c + b^{2}}\right )}{2 a}} \]