5.15 problem 15

Internal problem ID [93]

Book: Differential equations and linear algebra, 3rd ed., Edwards and Penney
Section: Section 1.6, Substitution methods and exact equations. Page 74
Problem number: 15.
ODE order: 1.
ODE degree: 1.

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

\[ \boxed {y \left (3 x +y\right )+x \left (x +y\right ) y^{\prime }=0} \]

Solution by Maple

Time used: 0.031 (sec). Leaf size: 59

dsolve(y(x)*(3*x+y(x))+x*(x+y(x))*diff(y(x),x) = 0,y(x), singsol=all)
 

\begin{align*} y \left (x \right ) = \frac {-c_{1} x^{2}-\sqrt {c_{1}^{2} x^{4}+1}}{c_{1} x} y \left (x \right ) = \frac {-c_{1} x^{2}+\sqrt {c_{1}^{2} x^{4}+1}}{c_{1} x} \end{align*}

Solution by Mathematica

Time used: 0.607 (sec). Leaf size: 93

DSolve[y[x]*(3*x+y[x])+x*(x+y[x])*y'[x] == 0,y[x],x,IncludeSingularSolutions -> True]
 

\begin{align*} y(x)\to -\frac {x^2+\sqrt {x^4+e^{2 c_1}}}{x} y(x)\to -x+\frac {\sqrt {x^4+e^{2 c_1}}}{x} y(x)\to -\frac {\sqrt {x^4}+x^2}{x} y(x)\to \frac {\sqrt {x^4}}{x}-x \end{align*}