2.186 problem 762

2.186.1 Maple step by step solution

Internal problem ID [9096]
Internal file name [OUTPUT/8031_Monday_June_06_2022_01_20_07_AM_90332965/index.tex]

Book: Differential Gleichungen, E. Kamke, 3rd ed. Chelsea Pub. NY, 1948
Section: Chapter 1, Additional non-linear first order
Problem number: 762.
ODE order: 1.
ODE degree: 1.

The type(s) of ODE detected by this program : "unknown"

Maple gives the following as the ode type

[[_1st_order, `_with_symmetry_[F(x),G(x)*y+H(x)]`]]

Unable to solve or complete the solution.

\[ \boxed {y^{\prime }+\frac {\left (\ln \left (y\right ) x +\ln \left (y\right )-x \right ) y}{x \left (x +1\right )}=0} \] Unable to determine ODE type.

2.186.1 Maple step by step solution

\[ \begin {array}{lll} & {} & \textrm {Let's solve}\hspace {3pt} \\ {} & {} & x^{2} y^{\prime }+\ln \left (y\right ) y x +y^{\prime } x +y \ln \left (y\right )-x y=0 \\ \bullet & {} & \textrm {Highest derivative means the order of the ODE is}\hspace {3pt} 1 \\ {} & {} & y^{\prime } \\ \bullet & {} & \textrm {Solve for the highest derivative}\hspace {3pt} \\ {} & {} & y^{\prime }=\frac {-\ln \left (y\right ) y x -y \ln \left (y\right )+x y}{x^{2}+x} \end {array} \]

Maple trace

`Methods for first order ODEs: 
--- Trying classification methods --- 
trying a quadrature 
trying 1st order linear 
trying Bernoulli 
trying separable 
trying inverse linear 
trying homogeneous types: 
trying Chini 
differential order: 1; looking for linear symmetries 
trying exact 
Looking for potential symmetries 
trying inverse_Riccati 
trying an equivalence to an Abel ODE 
differential order: 1; trying a linearization to 2nd order 
--- trying a change of variables {x -> y(x), y(x) -> x} 
differential order: 1; trying a linearization to 2nd order 
trying 1st order ODE linearizable_by_differentiation 
--- Trying Lie symmetry methods, 1st order --- 
`, `-> Computing symmetries using: way = 3 
`, `-> Computing symmetries using: way = 4`[0, y/x]
 

Solution by Maple

Time used: 0.016 (sec). Leaf size: 22

dsolve(diff(y(x),x) = -(ln(y(x))*x+ln(y(x))-x)*y(x)/x/(x+1),y(x), singsol=all)
 

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

Solution by Mathematica

Time used: 0.331 (sec). Leaf size: 26

DSolve[y'[x] == ((x - Log[y[x]] - x*Log[y[x]])*y[x])/(x*(1 + x)),y[x],x,IncludeSingularSolutions -> True]
 

\[ y(x)\to (x+1)^{-1/x} e^{1-\frac {c_1}{x}} \]