21.1 problem 23

Internal problem ID [2354]

Book: Differential Equations by Alfred L. Nelson, Karl W. Folley, Max Coral. 3rd ed. DC heath. Boston. 1964
Section: Exercise 39, page 179
Problem number: 23.
ODE order: 1.
ODE degree: 2.

CAS Maple gives this as type [[_1st_order, _with_linear_symmetries], _Clairaut]

\[ \boxed {y-y^{\prime } x -{y^{\prime }}^{2}=0} \]

Solution by Maple

Time used: 0.015 (sec). Leaf size: 19

dsolve(y(x)=diff(y(x),x)*x+diff(y(x),x)^2,y(x), singsol=all)
 

\begin{align*} y \left (x \right ) = -\frac {x^{2}}{4} y \left (x \right ) = c_{1}^{2}+c_{1} x \end{align*}

Solution by Mathematica

Time used: 0.006 (sec). Leaf size: 23

DSolve[y[x]==y'[x]*x+y'[x]^2,y[x],x,IncludeSingularSolutions -> True]
 

\begin{align*} y(x)\to c_1 (x+c_1) y(x)\to -\frac {x^2}{4} \end{align*}