12.1.1 problem Problem 14.2 (a)

Internal problem ID [3457]
Book : Mathematical methods for physics and engineering, Riley, Hobson, Bence, second edition, 2002
Section : Chapter 14, First order ordinary differential equations. 14.4 Exercises, page 490
Problem number : Problem 14.2 (a)
Date solved : Tuesday, September 30, 2025 at 06:38:55 AM
CAS classification : [_separable]

\begin{align*} y^{\prime }-x y^{3}&=0 \end{align*}
Maple. Time used: 0.001 (sec). Leaf size: 27
ode:=diff(y(x),x)-x*y(x)^3 = 0; 
dsolve(ode,y(x), singsol=all);
 
\begin{align*} y &= \frac {1}{\sqrt {-x^{2}+c_1}} \\ y &= -\frac {1}{\sqrt {-x^{2}+c_1}} \\ \end{align*}
Mathematica. Time used: 0.095 (sec). Leaf size: 44
ode=D[y[x],x]-x*y[x]^3==0; 
ic={}; 
DSolve[{ode,ic},y[x],x,IncludeSingularSolutions->True]
 
\begin{align*} y(x)&\to -\frac {1}{\sqrt {-x^2-2 c_1}}\\ y(x)&\to \frac {1}{\sqrt {-x^2-2 c_1}}\\ y(x)&\to 0 \end{align*}
Sympy. Time used: 0.189 (sec). Leaf size: 29
from sympy import * 
x = symbols("x") 
y = Function("y") 
ode = Eq(-x*y(x)**3 + Derivative(y(x), x),0) 
ics = {} 
dsolve(ode,func=y(x),ics=ics)
 
\[ \left [ y{\left (x \right )} = - \sqrt {- \frac {1}{C_{1} + x^{2}}}, \ y{\left (x \right )} = \sqrt {- \frac {1}{C_{1} + x^{2}}}\right ] \]