Internal problem ID [8134]
Book: Differential Gleichungen, E. Kamke, 3rd ed. Chelsea Pub. NY, 1948
Section: Chapter 1, linear first order
Problem number: 556.
ODE order: 1.
ODE degree: 4.
CAS Maple gives this as type [_dAlembert]
\[ \boxed {\sqrt {{y^{\prime }}^{2}+1}+x {y^{\prime }}^{2}+y=0} \]
✓ Solution by Maple
Time used: 0.125 (sec). Leaf size: 585
dsolve((diff(y(x),x)^2+1)^(1/2)+x*diff(y(x),x)^2+y(x)=0,y(x), singsol=all)
\begin{align*} y \left (x \right ) = -1 \\ \frac {x^{2} c_{1}}{{\left (\sqrt {-4 x y \left (x \right )+2+2 \sqrt {4 x^{2}-4 x y \left (x \right )+1}}-2 x \right )}^{2}}+x +\frac {2 x^{2} \left (\sqrt {2}\, \sqrt {\frac {2 x^{2}-2 x y \left (x \right )+\sqrt {4 x^{2}-4 x y \left (x \right )+1}+1}{x^{2}}}-2 \,\operatorname {arcsinh}\left (\frac {\sqrt {-4 x y \left (x \right )+2+2 \sqrt {4 x^{2}-4 x y \left (x \right )+1}}}{2 x}\right )\right )}{{\left (\sqrt {-4 x y \left (x \right )+2+2 \sqrt {4 x^{2}-4 x y \left (x \right )+1}}-2 x \right )}^{2}} = 0 \\ \frac {x^{2} c_{1}}{{\left (\sqrt {-4 x y \left (x \right )+2+2 \sqrt {4 x^{2}-4 x y \left (x \right )+1}}+2 x \right )}^{2}}+x +\frac {2 x^{2} \left (\sqrt {2}\, \sqrt {\frac {2 x^{2}-2 x y \left (x \right )+\sqrt {4 x^{2}-4 x y \left (x \right )+1}+1}{x^{2}}}+2 \,\operatorname {arcsinh}\left (\frac {\sqrt {-4 x y \left (x \right )+2+2 \sqrt {4 x^{2}-4 x y \left (x \right )+1}}}{2 x}\right )\right )}{{\left (\sqrt {-4 x y \left (x \right )+2+2 \sqrt {4 x^{2}-4 x y \left (x \right )+1}}+2 x \right )}^{2}} = 0 \\ \frac {x^{2} c_{1}}{{\left (\sqrt {-4 x y \left (x \right )-2 \sqrt {4 x^{2}-4 x y \left (x \right )+1}+2}-2 x \right )}^{2}}+x +\frac {2 x^{2} \left (2 \,\operatorname {arcsinh}\left (-\frac {\sqrt {-4 x y \left (x \right )-2 \sqrt {4 x^{2}-4 x y \left (x \right )+1}+2}}{2 x}\right )+\sqrt {\frac {4 x^{2}-4 x y \left (x \right )-2 \sqrt {4 x^{2}-4 x y \left (x \right )+1}+2}{x^{2}}}\right )}{{\left (\sqrt {-4 x y \left (x \right )-2 \sqrt {4 x^{2}-4 x y \left (x \right )+1}+2}-2 x \right )}^{2}} = 0 \\ \frac {x^{2} c_{1}}{{\left (\sqrt {-4 x y \left (x \right )-2 \sqrt {4 x^{2}-4 x y \left (x \right )+1}+2}+2 x \right )}^{2}}+x +\frac {2 x^{2} \left (2 \,\operatorname {arcsinh}\left (\frac {\sqrt {-4 x y \left (x \right )-2 \sqrt {4 x^{2}-4 x y \left (x \right )+1}+2}}{2 x}\right )+\sqrt {\frac {4 x^{2}-4 x y \left (x \right )-2 \sqrt {4 x^{2}-4 x y \left (x \right )+1}+2}{x^{2}}}\right )}{{\left (\sqrt {-4 x y \left (x \right )-2 \sqrt {4 x^{2}-4 x y \left (x \right )+1}+2}+2 x \right )}^{2}} = 0 \\ \end{align*}
✓ Solution by Mathematica
Time used: 3.286 (sec). Leaf size: 78
DSolve[y[x] + x*y'[x]^2 + Sqrt[1 + y'[x]^2]==0,y[x],x,IncludeSingularSolutions -> True]
\[ \text {Solve}\left [\left \{x=\frac {\log \left (\sqrt {K[1]^2+1}-K[1]\right )-\sqrt {K[1]^2+1}}{(K[1]+1)^2}+\frac {c_1}{(K[1]+1)^2},y(x)=-x K[1]^2-\sqrt {K[1]^2+1}\right \},\{y(x),K[1]\}\right ] \]