7.129 problem 1720 (book 6.129)

Internal problem ID [10041]
Internal file name [OUTPUT/8988_Monday_June_06_2022_06_08_33_AM_38018119/index.tex]

Book: Differential Gleichungen, E. Kamke, 3rd ed. Chelsea Pub. NY, 1948
Section: Chapter 6, non-linear second order
Problem number: 1720 (book 6.129).
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_linear_symmetries]]

Unable to solve or complete the solution.

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

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 
trying 2nd order ODE linearizable_by_differentiation 
trying 2nd order, 2 integrating factors of the form mu(x,y) 
trying a symmetry of the form [xi=0, eta=F(x)] 
checking if the LODE is missing y 
-> Heun: Equivalence to the GHE or one of its 4 confluent cases under a power @ Moebius 
-> trying a solution of the form r0(x) * Y + r1(x) * Y where Y = exp(int(r(x), dx)) * 2F1([a1, a2], [b1], f) 
-> Trying changes of variables to rationalize or make the ODE simpler 
<- unable to find a useful change of variables 
   trying a symmetry of the form [xi=0, eta=F(x)] 
   trying 2nd order exact linear 
   trying symmetries linear in x and y(x) 
   trying to convert to a linear ODE with constant coefficients 
   trying 2nd order, integrating factor of the form mu(x,y) 
   trying to convert to an ODE of Bessel type 
   -> trying reduction of order to Riccati 
      trying Riccati sub-methods: 
         trying Riccati_symmetries 
         -> trying a symmetry pattern of the form [F(x)*G(y), 0] 
         -> trying a symmetry pattern of the form [0, F(x)*G(y)] 
         -> trying a symmetry pattern of the form [F(x),G(x)*y+H(x)] 
trying differential order: 2; missing variables 
-> trying 2nd order, dynamical_symmetries, fully reducible to Abel through one integrating factor of the form G(x,y)/(1+H(x,y)*y)^2 
   --- trying a change of variables {x -> y(x), y(x) -> x} and re-entering methods for dynamical symmetries --- 
   -> trying 2nd order, dynamical_symmetries, fully reducible to Abel through one integrating factor of the form G(x,y)/(1+H(x,y)*y) 
trying 2nd order, integrating factors of the form mu(x,y)/(y)^n, only the singular cases 
         *** Sublevel 2 *** 
         Methods for first order ODEs: 
         --- Trying classification methods --- 
         trying a quadrature 
         trying 1st order linear 
         <- 1st order linear successful 
-> Calling odsolve with the ODE`, diff(diff(y(x), x), x)-(diff(y(x), x))*f(x)+(-(diff(f(x), x))+g(x)*(a+1))*y(x), y(x)`   *** Sublev 
   Methods for second order ODEs: 
integrating factor(s) found: eval(DESol({g(y)*_Y(y)*a-_Y(y)*diff(f(y),y)+g(y)*_Y(y)-f(y)*diff(_Y(y),y)+diff(diff(_Y(y),y),y)},{_Y(y) 
   attempting the computation of a related first integral... 
trying symmetries linear in x and y(x) 
`, `-> Computing symmetries using: way = 3 
`, `-> Computing symmetries using: way = exp_sym 
Try integration with the canonical coordinates of the symmetry [0, y] 
-> Calling odsolve with the ODE`, diff(_b(_a), _a) = -a*_b(_a)^2-_b(_a)^2-f(_a)*_b(_a)-g(_a), _b(_a), explicit`   *** Sublevel 2 *** 
   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 Riccati 
   trying Riccati sub-methods: 
      trying Riccati_symmetries 
      trying Riccati to 2nd Order 
      -> Calling odsolve with the ODE`, diff(diff(y(x), x), x) = -(diff(y(x), x))*f(x)-g(x)*(a+1)*y(x), y(x)`         *** Sublevel 3 
         Methods for second order ODEs: 
      -> Trying a change of variables to reduce to Bernoulli 
      -> Calling odsolve with the ODE`, diff(y(x), x)-((-a-1)*y(x)^2+y(x)-f(x)*y(x)*x-x^2*g(x))/x, y(x), explicit`         *** Suble 
         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 Riccati 
         trying Riccati sub-methods: 
            trying Riccati_symmetries 
         trying inverse_Riccati 
         trying 1st order ODE linearizable_by_differentiation 
      -> trying a symmetry pattern of the form [F(x)*G(y), 0] 
      -> trying a symmetry pattern of the form [0, F(x)*G(y)] 
      -> trying a symmetry pattern of the form [F(x),G(x)*y+H(x)] 
   trying inverse_Riccati 
   trying 1st order ODE linearizable_by_differentiation`
 

Solution by Maple

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

\[ \text {No solution found} \]

Solution by Mathematica

Time used: 0.0 (sec). Leaf size: 0

DSolve[g[x]*y[x]^2 + f[x]*y[x]*y'[x] + a*y'[x]^2 + y[x]*y''[x] == 0,y[x],x,IncludeSingularSolutions -> True]
 

Not solved