7.41 problem 1631 (6.41)

Internal problem ID [9953]
Internal file name [OUTPUT/8900_Monday_June_06_2022_05_48_00_AM_59041684/index.tex]

Book: Differential Gleichungen, E. Kamke, 3rd ed. Chelsea Pub. NY, 1948
Section: Chapter 6, non-linear second order
Problem number: 1631 (6.41).
ODE order: 2.
ODE degree: 1.

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

Maple gives the following as the ode type

[[_2nd_order, _with_potential_symmetries]]

Unable to solve or complete the solution.

\[ \boxed {y^{\prime \prime }-\left (3 y+f \left (x \right )\right ) y^{\prime }+y^{3}+y^{2} f \left (x \right )=0} \]

Maple trace

`Methods for second order ODEs: 
--- Trying classification methods --- 
trying 2nd order Liouville 
trying 2nd order WeierstrassP 
trying 2nd order JacobiSN 
differential order: 2; trying a linearization to 3rd order 
-> Calling odsolve with the ODE`, diff(diff(diff(y(x), x), x), x) = f(x)*(diff(diff(y(x), x), x)), y(x)`   *** Sublevel 2 *** 
   Methods for third order ODEs: 
   --- Trying classification methods --- 
   trying a quadrature 
   checking if the LODE has constant coefficients 
   checking if the LODE is of Euler type 
   trying high order exact linear fully integrable 
   -> Calling odsolve with the ODE`, diff(_b(_a), _a) = f(_a)*_b(_a), _b(_a)`      *** Sublevel 3 *** 
      Methods for first order ODEs: 
      --- Trying classification methods --- 
      trying a quadrature 
      trying 1st order linear 
      <- 1st order linear successful 
   <- high order exact linear fully integrable successful 
<- differential order: 2; linearization to 3rd order successful`
 

Solution by Maple

Time used: 0.0 (sec). Leaf size: 37

dsolve(diff(diff(y(x),x),x)-(3*y(x)+f(x))*diff(y(x),x)+y(x)^3+y(x)^2*f(x)=0,y(x), singsol=all)
 

\[ y \left (x \right ) = \frac {-c_{1} \left (\int {\mathrm e}^{\int f \left (x \right )d x}d x \right )-c_{2}}{c_{1} \left (\int \int {\mathrm e}^{\int f \left (x \right )d x}d x d x \right )+c_{2} x +1} \]

Solution by Mathematica

Time used: 60.069 (sec). Leaf size: 72

DSolve[f[x]*y[x]^2 + y[x]^3 - (f[x] + 3*y[x])*y'[x] + y''[x] == 0,y[x],x,IncludeSingularSolutions -> True]
 

\[ y(x)\to -\frac {\int _1^x\exp \left (\int _1^{K[2]}f(K[1])dK[1]\right ) c_1dK[2]+c_2}{\int _1^x\int _1^{K[5]}\exp \left (\int _1^{K[4]}f(K[3])dK[3]\right ) c_1dK[4]dK[5]+c_2 x+1} \]