90.7.15 problem 15

Internal problem ID [25169]
Book : Ordinary Differential Equations. By William Adkins and Mark G Davidson. Springer. NY. 2010. ISBN 978-1-4614-3617-1
Section : Chapter 1. First order differential equations. Exercises at page 99
Problem number : 15
Date solved : Thursday, October 02, 2025 at 11:56:13 PM
CAS classification : [_quadrature]

\begin{align*} y^{\prime }&=a y \end{align*}

With initial conditions

\begin{align*} y \left (0\right )&=1 \\ \end{align*}

✓ Maple. Time used: 0.006 (sec). Leaf size: 8

ode:=diff(y(t),t) = a*y(t); 
ic:=[y(0) = 1]; 
dsolve([ode,op(ic)],y(t), singsol=all);
 

\[ y = {\mathrm e}^{a t} \]

✓ Mathematica. Time used: 0.014 (sec). Leaf size: 10

ode=D[y[t],t]== a*y[t]; 
ic={y[0]==1}; 
DSolve[{ode,ic},y[t],t,IncludeSingularSolutions->True]
 

\begin{align*} y(t)&\to e^{a t} \end{align*}

✓ Sympy. Time used: 0.063 (sec). Leaf size: 7

from sympy import * 
t = symbols("t") 
y = Function("y") 
ode = Eq(-a*y(t) + Derivative(y(t), t),0) 
ics = {y(0): 1} 
dsolve(ode,func=y(t),ics=ics)
 

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