4.8 problem Problem 16

Internal problem ID [2672]

Book: Differential equations and linear algebra, Stephen W. Goode and Scott A Annin. Fourth edition, 2015
Section: Chapter 1, First-Order Differential Equations. Section 1.8, Change of Variables. page 79
Problem number: Problem 16.
ODE order: 1.
ODE degree: 1.

CAS Maple gives this as type [[_homogeneous, `class A`], _dAlembert]

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

Solution by Maple

Time used: 0.031 (sec). Leaf size: 12

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

\[ y \left (x \right ) = x \,{\mathrm e}^{c_{1} x +1} \]

Solution by Mathematica

Time used: 0.257 (sec). Leaf size: 24

DSolve[x*y'[x]+y[x]*Log[x]==y[x]*Log[y[x]],y[x],x,IncludeSingularSolutions -> True]
 

\begin{align*} y(x)\to x e^{1+e^{c_1} x} \\ y(x)\to e x \\ \end{align*}