60.1.473 problem 486

Internal problem ID [10487]
Book : Differential Gleichungen, E. Kamke, 3rd ed. Chelsea Pub. NY, 1948
Section : Chapter 1, linear first order
Problem number : 486
Date solved : Sunday, March 30, 2025 at 05:07:10 PM
CAS classification : [_quadrature]

\begin{align*} y^{2} {y^{\prime }}^{2}+y^{2}-a^{2}&=0 \end{align*}

✓ Maple. Time used: 0.101 (sec). Leaf size: 54

ode:=y(x)^2*diff(y(x),x)^2+y(x)^2-a^2 = 0; 
dsolve(ode,y(x), singsol=all);
 

\begin{align*} y &= -a \\ y &= a \\ y &= \sqrt {-c_1^{2}+2 c_1 x +a^{2}-x^{2}} \\ y &= -\sqrt {\left (a +x -c_1 \right ) \left (c_1 +a -x \right )} \\ \end{align*}

✓ Mathematica. Time used: 0.218 (sec). Leaf size: 101

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

\begin{align*} y(x)\to -\sqrt {a^2-(x+c_1){}^2} \\ y(x)\to \sqrt {a^2-(x+c_1){}^2} \\ y(x)\to -\sqrt {a^2-(x-c_1){}^2} \\ y(x)\to \sqrt {a^2-(x-c_1){}^2} \\ y(x)\to -a \\ y(x)\to a \\ \end{align*}

✓ Sympy. Time used: 3.774 (sec). Leaf size: 85

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

\[ \left [ y{\left (x \right )} = - \sqrt {- C_{1}^{2} + 2 C_{1} x + a^{2} - x^{2}}, \ y{\left (x \right )} = \sqrt {- C_{1}^{2} + 2 C_{1} x + a^{2} - x^{2}}, \ y{\left (x \right )} = - \sqrt {- C_{1}^{2} - 2 C_{1} x + a^{2} - x^{2}}, \ y{\left (x \right )} = \sqrt {- C_{1}^{2} - 2 C_{1} x + a^{2} - x^{2}}\right ] \]