22.6 problem 1(f)

Internal problem ID [5331]

Book: An introduction to Ordinary Differential Equations. Earl A. Coddington. Dover. NY 1961
Section: Chapter 5. Existence and uniqueness of solutions to first order equations. Page 198
Problem number: 1(f).
ODE order: 1.
ODE degree: 1.

CAS Maple gives this as type [[_homogeneous, class A], _exact, _rational, [_Abel, 2nd type, class A]]

Solve \begin {gather*} \boxed {x +y+\left (x -y\right ) y^{\prime }=0} \end {gather*}

Solution by Maple

Time used: 0.125 (sec). Leaf size: 49

dsolve((x+y(x))+(x-y(x))*diff(y(x),x)=0,y(x), singsol=all)
 

\begin{align*} y \relax (x ) = \frac {c_{1} x -\sqrt {2 x^{2} c_{1}^{2}+1}}{c_{1}} \\ y \relax (x ) = \frac {c_{1} x +\sqrt {2 x^{2} c_{1}^{2}+1}}{c_{1}} \\ \end{align*}

Solution by Mathematica

Time used: 0.724 (sec). Leaf size: 86

DSolve[(x+y[x])+(x-y[x])*y'[x]==0,y[x],x,IncludeSingularSolutions -> True]
 

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