7.140 problem 1730

Internal problem ID [9309]

Book: Differential Gleichungen, E. Kamke, 3rd ed. Chelsea Pub. NY, 1948
Section: Chapter 6, non-linear second order
Problem number: 1730.
ODE order: 2.
ODE degree: 1.

CAS Maple gives this as type [[_2nd_order, _missing_x]]

Solve \begin {gather*} \boxed {2 y^{\prime \prime } y-\left (y^{\prime }\right )^{2}-8 y^{3}=0} \end {gather*}

Solution by Maple

Time used: 0.08 (sec). Leaf size: 57

dsolve(2*diff(diff(y(x),x),x)*y(x)-diff(y(x),x)^2-8*y(x)^3=0,y(x), singsol=all)
 

\begin{align*} y \relax (x ) = 0 \\ \int _{}^{y \relax (x )}\frac {1}{\sqrt {4 \textit {\_a}^{3}+\textit {\_a} c_{1}}}d \textit {\_a} -x -c_{2} = 0 \\ \int _{}^{y \relax (x )}-\frac {1}{\sqrt {4 \textit {\_a}^{3}+\textit {\_a} c_{1}}}d \textit {\_a} -x -c_{2} = 0 \\ \end{align*}

Solution by Mathematica

Time used: 0.552 (sec). Leaf size: 135

DSolve[-8*y[x]^3 - y'[x]^2 + 2*y[x]*y''[x] == 0,y[x],x,IncludeSingularSolutions -> True]
 

\begin{align*} y(x)\to \text {InverseFunction}\left [-\frac {2 \sqrt {\text {$\#$1}} \sqrt {1+\frac {4 \text {$\#$1}^2}{c_1}} \, _2F_1\left (\frac {1}{4},\frac {1}{2};\frac {5}{4};-\frac {4 \text {$\#$1}^2}{c_1}\right )}{\sqrt {4 \text {$\#$1}^2+c_1}}\&\right ][x+c_2] \\ y(x)\to \text {InverseFunction}\left [\frac {2 \sqrt {\text {$\#$1}} \sqrt {1+\frac {4 \text {$\#$1}^2}{c_1}} \, _2F_1\left (\frac {1}{4},\frac {1}{2};\frac {5}{4};-\frac {4 \text {$\#$1}^2}{c_1}\right )}{\sqrt {4 \text {$\#$1}^2+c_1}}\&\right ][x+c_2] \\ \end{align*}