15.2.11 problem 11

Internal problem ID [2881]
Book : Differential Equations by Alfred L. Nelson, Karl W. Folley, Max Coral. 3rd ed. DC heath. Boston. 1964
Section : Exercise 6, page 25
Problem number : 11
Date solved : Monday, January 27, 2025 at 06:23:31 AM
CAS classification : [[_homogeneous, `class A`], _exact, _rational, [_Abel, `2nd type`, `class A`]]

\begin{align*} x +y+\left (x -y\right ) y^{\prime }&=0 \end{align*}

Solution by Maple

Time used: 0.046 (sec). Leaf size: 49

dsolve((x+y(x))+(x-y(x))*diff(y(x),x)=0,y(x), singsol=all)
 
\begin{align*} y &= \frac {c_1 x -\sqrt {2 c_1^{2} x^{2}+1}}{c_1} \\ y &= \frac {c_1 x +\sqrt {2 c_1^{2} x^{2}+1}}{c_1} \\ \end{align*}

Solution by Mathematica

Time used: 0.451 (sec). Leaf size: 86

DSolve[(x+y[x])+(x-y[x])*D[y[x],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*}