8.8 problem 1844

Internal problem ID [10166]
Internal file name [OUTPUT/9113_Monday_June_06_2022_06_41_01_AM_90337484/index.tex]

Book: Differential Gleichungen, E. Kamke, 3rd ed. Chelsea Pub. NY, 1948
Section: Chapter 7, non-linear third and higher order
Problem number: 1844.
ODE order: 3.
ODE degree: 1.

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

Maple gives the following as the ode type

[[_3rd_order, _missing_x], [_3rd_order, _with_linear_symmetries]]

Unable to solve or complete the solution.

Unable to parse ODE.

Maple trace

`Methods for third order ODEs: 
--- Trying classification methods --- 
trying 3rd order ODE linearizable_by_differentiation 
differential order: 3; trying a linearization to 4th order 
trying differential order: 3; missing variables 
`, `-> Computing symmetries using: way = 3 
Try integration with the canonical coordinates of the symmetry [0, y] 
-> Calling odsolve with the ODE`, (1/4)*_b(_a)^3-(3/2)*(diff(_b(_a), _a))*_b(_a)+diff(diff(_b(_a), _a), _a) = 0, _b(_a), explicit, H 
   symmetry methods on request 
`, `2nd order, trying reduction of order with given symmetries:`[1, 0], [_a, -_b]
 

Solution by Maple

Time used: 0.094 (sec). Leaf size: 77

dsolve(4*y(x)^2*diff(diff(diff(y(x),x),x),x)-18*y(x)*diff(y(x),x)*diff(diff(y(x),x),x)+15*diff(y(x),x)^3=0,y(x), singsol=all)
 

\begin{align*} y \left (x \right ) &= 0 \\ y \left (x \right ) &= {\mathrm e}^{\int \operatorname {RootOf}\left (-2 \left (\int _{}^{\textit {\_Z}}\frac {1}{\textit {\_h}^{2}+\sqrt {c_{1} \left (\textit {\_h}^{2}+c_{1} \right )}+c_{1}}d \textit {\_h} \right )+x +c_{2} \right )d x +c_{3}} \\ y \left (x \right ) &= {\mathrm e}^{\int \operatorname {RootOf}\left (2 \left (\int _{}^{\textit {\_Z}}-\frac {1}{\textit {\_h}^{2}-\sqrt {c_{1} \left (\textit {\_h}^{2}+c_{1} \right )}+c_{1}}d \textit {\_h} \right )+x +c_{2} \right )d x +c_{3}} \\ \end{align*}

Solution by Mathematica

Time used: 0.199 (sec). Leaf size: 19

DSolve[15*y'[x]^3 - 18*y[x]*y'[x]*y''[x] + 4*y[x]^2*Derivative[3][y][x] == 0,y[x],x,IncludeSingularSolutions -> True]
 

\[ y(x)\to \frac {1}{(x (c_3 x+c_2)+c_1){}^2} \]