29.7 problem 829

Internal problem ID [4068]

Book: Ordinary differential equations and their solutions. By George Moseley Murphy. 1960
Section: Various 29
Problem number: 829.
ODE order: 1.
ODE degree: 2.

CAS Maple gives this as type [[_1st_order, _with_linear_symmetries]]

\[ \boxed {{y^{\prime }}^{2}-3 x y^{\frac {2}{3}} y^{\prime }+9 y^{\frac {5}{3}}=0} \]

Solution by Maple

Time used: 0.172 (sec). Leaf size: 141

dsolve(diff(y(x),x)^2-3*x*y(x)^(2/3)*diff(y(x),x)+9*y(x)^(5/3) = 0,y(x), singsol=all)
 

\begin{align*} y \left (x \right ) = \frac {x^{6}}{64} y \left (x \right ) = 0 \ln \left (x \right )+\frac {\sqrt {-4 \left (\frac {y \left (x \right )}{x^{6}}\right )^{\frac {5}{3}}+\left (\frac {y \left (x \right )}{x^{6}}\right )^{\frac {4}{3}}}\, \operatorname {arctanh}\left (\sqrt {-4 \left (\frac {y \left (x \right )}{x^{6}}\right )^{\frac {1}{3}}+1}\right )}{\left (\frac {y \left (x \right )}{x^{6}}\right )^{\frac {2}{3}} \sqrt {-4 \left (\frac {y \left (x \right )}{x^{6}}\right )^{\frac {1}{3}}+1}}+\frac {\ln \left (\frac {64 y \left (x \right )}{x^{6}}-1\right )}{6}-\frac {\ln \left (4 \left (\frac {y \left (x \right )}{x^{6}}\right )^{\frac {1}{3}}-1\right )}{6}-\frac {\ln \left (16 \left (\frac {y \left (x \right )}{x^{6}}\right )^{\frac {2}{3}}+4 \left (\frac {y \left (x \right )}{x^{6}}\right )^{\frac {1}{3}}+1\right )}{6}+\frac {\ln \left (\frac {y \left (x \right )}{x^{6}}\right )}{6}-c_{1} = 0 \end{align*}

Solution by Mathematica

Time used: 17.485 (sec). Leaf size: 701

DSolve[(y'[x])^2-3 x y[x]^(2/3) y'[x]+9 y[x]^(5/3)==0,y[x],x,IncludeSingularSolutions -> True]
 

\begin{align*} \text {Solve}\left [\frac {8 x^2 \log (y(x))-6 \sqrt {x^4} \log \left (x^2 \sqrt {x^2-4 \sqrt [3]{y(x)}}\right )-3 \sqrt {x^4} \log \left (4 \sqrt [3]{y(x)}-x^2\right )+6 \left (\sqrt {x^4}-x^2\right ) \log \left (16 x^2 \sqrt {x^2 y(x)^{4/3}-4 y(x)^{5/3}}+x^6 \left (-\sqrt {x^2-4 \sqrt [3]{y(x)}}\right )-\sqrt {x^4} \sqrt {x^2-4 \sqrt [3]{y(x)}} \left (x^4-16 y(x)^{2/3}\right )\right )+6 \left (\sqrt {x^4}+x^2\right ) \log \left (16 x^2 \sqrt {x^2 y(x)^{4/3}-4 y(x)^{5/3}}+x^6 \sqrt {x^2-4 \sqrt [3]{y(x)}}-\sqrt {x^4} \sqrt {x^2-4 \sqrt [3]{y(x)}} \left (x^4-16 y(x)^{2/3}\right )\right )}{48 x^2}-\frac {\sqrt {\left (x^2-4 \sqrt [3]{y(x)}\right ) y(x)^{4/3}} \log \left (\sqrt {x^2-4 \sqrt [3]{y(x)}}-x\right )}{\sqrt {x^2-4 \sqrt [3]{y(x)}} y(x)^{2/3}}=c_1,y(x)\right ] \text {Solve}\left [\frac {\sqrt {\left (x^2-4 \sqrt [3]{y(x)}\right ) y(x)^{4/3}} \log \left (\sqrt {x^2-4 \sqrt [3]{y(x)}}-x\right )}{\sqrt {x^2-4 \sqrt [3]{y(x)}} y(x)^{2/3}}+\frac {8 x^2 \log (y(x))+6 \sqrt {x^4} \log \left (x^2 \sqrt {x^2-4 \sqrt [3]{y(x)}}\right )+3 \sqrt {x^4} \log \left (4 \sqrt [3]{y(x)}-x^2\right )+6 \left (x^2-\sqrt {x^4}\right ) \log \left (16 x^2 \sqrt {x^2 y(x)^{4/3}-4 y(x)^{5/3}}+x^6 \left (-\sqrt {x^2-4 \sqrt [3]{y(x)}}\right )-\sqrt {x^4} \sqrt {x^2-4 \sqrt [3]{y(x)}} \left (x^4-16 y(x)^{2/3}\right )\right )-6 \left (\sqrt {x^4}+x^2\right ) \log \left (16 x^2 \sqrt {x^2 y(x)^{4/3}-4 y(x)^{5/3}}+x^6 \sqrt {x^2-4 \sqrt [3]{y(x)}}-\sqrt {x^4} \sqrt {x^2-4 \sqrt [3]{y(x)}} \left (x^4-16 y(x)^{2/3}\right )\right )}{48 x^2}=c_1,y(x)\right ] y(x)\to 0 \end{align*}