73.8.14 problem 13.2 (h)

Internal problem ID [15151]
Book : Ordinary Differential Equations. An introduction to the fundamentals. Kenneth B. Howell. second edition. CRC Press. FL, USA. 2020
Section : Chapter 13. Higher order equations: Extending first order concepts. Additional exercises page 259
Problem number : 13.2 (h)
Date solved : Monday, March 31, 2025 at 01:29:24 PM
CAS classification : [[_2nd_order, _missing_x], _Liouville, [_2nd_order, _reducible, _mu_x_y1], [_2nd_order, _reducible, _mu_xy]]

\begin{align*} \left (y-3\right ) y^{\prime \prime }&=2 {y^{\prime }}^{2} \end{align*}

✓ Maple. Time used: 0.022 (sec). Leaf size: 25

ode:=(y(x)-3)*diff(diff(y(x),x),x) = 2*diff(y(x),x)^2; 
dsolve(ode,y(x), singsol=all);
 

\begin{align*} y &= 3 \\ y &= \frac {3 c_1 x +3 c_2 -1}{c_1 x +c_2} \\ \end{align*}

✓ Mathematica. Time used: 0.187 (sec). Leaf size: 44

ode=(y[x]-3)*D[y[x],{x,2}]==2*D[y[x],x]^2; 
ic={}; 
DSolve[{ode,ic},y[x],x,IncludeSingularSolutions->True]
 

\begin{align*} y(x)\to \frac {3 c_1 x-1+3 c_2 c_1}{c_1 (x+c_2)} \\ y(x)\to 3 \\ y(x)\to \text {Indeterminate} \\ y(x)\to 3 \\ \end{align*}

✗ Sympy

from sympy import * 
x = symbols("x") 
y = Function("y") 
ode = Eq((y(x) - 3)*Derivative(y(x), (x, 2)) - 2*Derivative(y(x), x)**2,0) 
ics = {} 
dsolve(ode,func=y(x),ics=ics)
 

NotImplementedError : The given ODE -sqrt(2)*sqrt((y(x) - 3)*Derivative(y(x), (x, 2)))/2 + Derivative(y(x), x) cannot be solved by the factorable group method