18.27 problem 505

Internal problem ID [3249]

Book: Ordinary differential equations and their solutions. By George Moseley Murphy. 1960
Section: Various 18
Problem number: 505.
ODE order: 1.
ODE degree: 1.

CAS Maple gives this as type [_separable]

Solve \begin {gather*} \boxed {y y^{\prime } x +1+y^{2}=0} \end {gather*}

Solution by Maple

Time used: 0.0 (sec). Leaf size: 34

dsolve(x*y(x)*diff(y(x),x)+1+y(x)^2 = 0,y(x), singsol=all)
 

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

Solution by Mathematica

Time used: 0.322 (sec). Leaf size: 96

DSolve[x y[x] y'[x]+1+y[x]^2==0,y[x],x,IncludeSingularSolutions -> True]
 

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