75.3.24 problem 24

Internal problem ID [19928]
Book : A short course on differential equations. By Donald Francis Campbell. Maxmillan company. London. 1907
Section : Chapter III. Ordinary differential equations of the first order and first degree. Exercises at page 33
Problem number : 24
Date solved : Thursday, October 02, 2025 at 05:02:28 PM
CAS classification : [[_homogeneous, `class A`], _rational, _dAlembert]

\begin{align*} \left (x^{2}+3 y x -y^{2}\right ) y^{\prime }-3 y^{2}&=0 \end{align*}
Maple. Time used: 0.153 (sec). Leaf size: 53
ode:=(x^2+3*x*y(x)-y(x)^2)*diff(y(x),x)-3*y(x)^2 = 0; 
dsolve(ode,y(x), singsol=all);
 
\[ y = x \operatorname {RootOf}\left (8+x^{2} c_1 \,\textit {\_Z}^{10}-2 x^{2} c_1 \,\textit {\_Z}^{8}+\left (c_1 \,x^{2}-1\right ) \textit {\_Z}^{6}+6 \textit {\_Z}^{4}-12 \textit {\_Z}^{2}\right )^{2}-x \]
Mathematica. Time used: 5.495 (sec). Leaf size: 396
ode=(x^2+3*x*y[x]-y[x]^2)*D[y[x],x]-(3*y[x]^2)==0; 
ic={}; 
DSolve[{ode,ic},y[x],x,IncludeSingularSolutions->True]
 
\begin{align*} y(x)&\to \text {Root}\left [\text {$\#$1}^5+3 \text {$\#$1}^4 x+\text {$\#$1}^3 \left (3 x^2+e^{2 c_1}\right )+\text {$\#$1}^2 \left (x^3-3 e^{2 c_1} x\right )+3 \text {$\#$1} e^{2 c_1} x^2-e^{2 c_1} x^3\&,1\right ]\\ y(x)&\to \text {Root}\left [\text {$\#$1}^5+3 \text {$\#$1}^4 x+\text {$\#$1}^3 \left (3 x^2+e^{2 c_1}\right )+\text {$\#$1}^2 \left (x^3-3 e^{2 c_1} x\right )+3 \text {$\#$1} e^{2 c_1} x^2-e^{2 c_1} x^3\&,2\right ]\\ y(x)&\to \text {Root}\left [\text {$\#$1}^5+3 \text {$\#$1}^4 x+\text {$\#$1}^3 \left (3 x^2+e^{2 c_1}\right )+\text {$\#$1}^2 \left (x^3-3 e^{2 c_1} x\right )+3 \text {$\#$1} e^{2 c_1} x^2-e^{2 c_1} x^3\&,3\right ]\\ y(x)&\to \text {Root}\left [\text {$\#$1}^5+3 \text {$\#$1}^4 x+\text {$\#$1}^3 \left (3 x^2+e^{2 c_1}\right )+\text {$\#$1}^2 \left (x^3-3 e^{2 c_1} x\right )+3 \text {$\#$1} e^{2 c_1} x^2-e^{2 c_1} x^3\&,4\right ]\\ y(x)&\to \text {Root}\left [\text {$\#$1}^5+3 \text {$\#$1}^4 x+\text {$\#$1}^3 \left (3 x^2+e^{2 c_1}\right )+\text {$\#$1}^2 \left (x^3-3 e^{2 c_1} x\right )+3 \text {$\#$1} e^{2 c_1} x^2-e^{2 c_1} x^3\&,5\right ]\\ y(x)&\to 0 \end{align*}
Sympy. Time used: 0.498 (sec). Leaf size: 27
from sympy import * 
x = symbols("x") 
y = Function("y") 
ode = Eq((x**2 + 3*x*y(x) - y(x)**2)*Derivative(y(x), x) - 3*y(x)**2,0) 
ics = {} 
dsolve(ode,func=y(x),ics=ics)
 
\[ \log {\left (y{\left (x \right )} \right )} = C_{1} + \log {\left (\frac {\left (\frac {x}{y{\left (x \right )}} - 1\right )^{\frac {3}{2}}}{\left (\frac {x}{y{\left (x \right )}} + 1\right )^{\frac {3}{2}}} \right )} \]