1.9 problem 9

Internal problem ID [6022]

Book: Elementary differential equations. By Earl D. Rainville, Phillip E. Bedient. Macmilliam Publishing Co. NY. 6th edition. 1981.
Section: CHAPTER 16. Nonlinear equations. Section 94. Factoring the left member. EXERCISES Page 309
Problem number: 9.
ODE order: 1.
ODE degree: 2.

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

Solve \begin {gather*} \boxed {\left (x +y\right )^{2} \left (y^{\prime }\right )^{2}-y^{2}=0} \end {gather*}

Solution by Maple

Time used: 0.019 (sec). Leaf size: 48

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

\begin{align*} y \relax (x ) = {\mathrm e}^{\LambertW \left (x \,{\mathrm e}^{c_{1}}\right )-c_{1}} \\ y \relax (x ) = -x -\sqrt {x^{2}+2 c_{1}} \\ y \relax (x ) = -x +\sqrt {x^{2}+2 c_{1}} \\ \end{align*}

Solution by Mathematica

Time used: 9.735 (sec). Leaf size: 95

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

\begin{align*} y(x)\to -x-\sqrt {x^2+c_1{}^2} \\ y(x)\to -x+\sqrt {x^2+c_1{}^2} \\ y(x)\to \frac {x}{\text {ProductLog}\left (\frac {x}{c_1}\right )} \\ y(x)\to 0 \\ y(x)\to -\sqrt {x^2}-x \\ y(x)\to \sqrt {x^2}-x \\ \end{align*}