2.25 problem 601

Internal problem ID [8181]

Book: Differential Gleichungen, E. Kamke, 3rd ed. Chelsea Pub. NY, 1948
Section: Chapter 1, Additional non-linear first order
Problem number: 601.
ODE order: 1.
ODE degree: 1.

CAS Maple gives this as type [[_1st_order, _with_symmetry_[F(x),G(y)]]]

Solve \begin {gather*} \boxed {y^{\prime }-\frac {F \left (-\left (x -y\right ) \left (x +y\right )\right ) x}{y}=0} \end {gather*}

Solution by Maple

Time used: 0.651 (sec). Leaf size: 91

dsolve(diff(y(x),x) = F(-(x-y(x))*(x+y(x)))*x/y(x),y(x), singsol=all)
 

\begin{align*} y \relax (x ) = \sqrt {x^{2}+\RootOf \left (F \left (\textit {\_Z} \right )-1\right )} \\ y \relax (x ) = -\sqrt {x^{2}+\RootOf \left (F \left (\textit {\_Z} \right )-1\right )} \\ y \relax (x ) = \sqrt {x^{2}+\RootOf \left (-x^{2}+\int _{}^{\textit {\_Z}}\frac {1}{F \left (\textit {\_a} \right )-1}d \textit {\_a} +2 c_{1}\right )} \\ y \relax (x ) = -\sqrt {x^{2}+\RootOf \left (-x^{2}+\int _{}^{\textit {\_Z}}\frac {1}{F \left (\textit {\_a} \right )-1}d \textit {\_a} +2 c_{1}\right )} \\ \end{align*}

Solution by Mathematica

Time used: 0.207 (sec). Leaf size: 182

DSolve[y'[x] == (x*F[(-x + y[x])*(x + y[x])])/y[x],y[x],x,IncludeSingularSolutions -> True]
 

\[ \text {Solve}\left [\int _1^{y(x)}\left (\frac {K[2]}{F((K[2]-x) (x+K[2]))-1}-\int _1^x\left (\frac {2 F((K[2]-K[1]) (K[1]+K[2])) K[1] K[2] F'((K[2]-K[1]) (K[1]+K[2]))}{(F((K[2]-K[1]) (K[1]+K[2]))-1)^2}-\frac {2 K[1] K[2] F'((K[2]-K[1]) (K[1]+K[2]))}{F((K[2]-K[1]) (K[1]+K[2]))-1}\right )dK[1]\right )dK[2]+\int _1^x-\frac {F((y(x)-K[1]) (K[1]+y(x))) K[1]}{F((y(x)-K[1]) (K[1]+y(x)))-1}dK[1]=c_1,y(x)\right ] \]