Internal problem ID [5448]
Book: Differential Equations: Theory, Technique, and Practice by George Simmons, Steven Krantz.
McGraw-Hill NY. 2007. 1st Edition.
Section: Chapter 1. What is a differential equation. Section 1.5. Exact Equations. Page
20
Problem number: 20.
ODE order: 1.
ODE degree: 1.
CAS Maple gives this as type [[_1st_order, _with_linear_symmetries], _exact, _rational]
Solve \begin {gather*} \boxed {\frac {y-x y^{\prime }}{\left (x +y\right )^{2}}+y^{\prime }-1=0} \end {gather*}
✓ Solution by Maple
Time used: 0.015 (sec). Leaf size: 65
dsolve((y(x)-x*diff(y(x),x))/(x+y(x))^2+diff(y(x),x)=1,y(x), singsol=all)
\begin{align*} y \relax (x ) = \frac {c_{1}}{4}+\frac {1}{4}-\frac {\sqrt {16 x^{2}+8 c_{1} x +c_{1}^{2}-8 x +2 c_{1}+1}}{4} \\ y \relax (x ) = \frac {c_{1}}{4}+\frac {1}{4}+\frac {\sqrt {16 x^{2}+8 c_{1} x +c_{1}^{2}-8 x +2 c_{1}+1}}{4} \\ \end{align*}
✓ Solution by Mathematica
Time used: 0.656 (sec). Leaf size: 70
DSolve[(y[x]-x*y'[x])/(x+y[x])^2+y'[x]==1,y[x],x,IncludeSingularSolutions -> True]
\begin{align*} y(x)\to \frac {1}{2} \left (-\sqrt {(2 x+c_1){}^2+1+2 c_1}+1+c_1\right ) \\ y(x)\to \frac {1}{2} \left (\sqrt {(2 x+c_1){}^2+1+2 c_1}+1+c_1\right ) \\ y(x)\to -x \\ \end{align*}