29.9 problem 831

Internal problem ID [4070]

Book: Ordinary differential equations and their solutions. By George Moseley Murphy. 1960
Section: Various 29
Problem number: 831.
ODE order: 1.
ODE degree: 2.

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

\[ \boxed {2 {y^{\prime }}^{2}+x y^{\prime }-2 y=0} \]

Solution by Maple

Time used: 0.047 (sec). Leaf size: 36

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

\[ y \left (x \right ) = {\mathrm e}^{2 \operatorname {LambertW}\left (\frac {x \,{\mathrm e}^{\frac {c_{1}}{4}}}{4}\right )-\frac {c_{1}}{2}}+\frac {x \,{\mathrm e}^{\operatorname {LambertW}\left (\frac {x \,{\mathrm e}^{\frac {c_{1}}{4}}}{4}\right )-\frac {c_{1}}{4}}}{2} \]

Solution by Mathematica

Time used: 1.193 (sec). Leaf size: 130

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

\begin{align*} \text {Solve}\left [-\frac {\frac {1}{2} x \sqrt {x^2+16 y(x)}-8 y(x) \log \left (\sqrt {x^2+16 y(x)}-x\right )+\frac {x^2}{2}}{8 y(x)}=c_1,y(x)\right ] \text {Solve}\left [\frac {\frac {1}{2} x \sqrt {x^2+16 y(x)}-8 y(x) \log \left (\sqrt {x^2+16 y(x)}-x\right )-\frac {x^2}{2}}{8 y(x)}+\log (y(x))=c_1,y(x)\right ] y(x)\to 0 \end{align*}