1.311 problem 312

Internal problem ID [8648]

Book: Differential Gleichungen, E. Kamke, 3rd ed. Chelsea Pub. NY, 1948
Section: Chapter 1, linear first order
Problem number: 312.
ODE order: 1.
ODE degree: 1.

CAS Maple gives this as type [_rational]

\[ \boxed {\left (\frac {y^{2}}{b}+\frac {x^{2}}{a}\right ) \left (x +y y^{\prime }\right )+\frac {\left (a -b \right ) \left (y y^{\prime }-x \right )}{a +b}=0} \]

Solution by Maple

Time used: 0.015 (sec). Leaf size: 244

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

\begin{align*} y \left (x \right ) &= \frac {\sqrt {a \left ({\mathrm e}^{\frac {-2 \operatorname {LambertW}\left (\frac {\left (a +b \right ) {\mathrm e}^{\frac {\left (-x^{2}-b \right ) a^{2}+\left (-b^{2}-2 c_{1} \right ) a +b^{2} x^{2}}{2 a^{2} b}}}{2 a^{2} b}\right ) a^{2} b +\left (-x^{2}-b \right ) a^{2}+\left (-b^{2}-2 c_{1} \right ) a +b^{2} x^{2}}{2 a^{2} b}}+b \left (-x^{2}+a \right )\right )}}{a} \\ y \left (x \right ) &= -\frac {\sqrt {a \left ({\mathrm e}^{\frac {-2 \operatorname {LambertW}\left (\frac {\left (a +b \right ) {\mathrm e}^{\frac {\left (-x^{2}-b \right ) a^{2}+\left (-b^{2}-2 c_{1} \right ) a +b^{2} x^{2}}{2 a^{2} b}}}{2 a^{2} b}\right ) a^{2} b +\left (-x^{2}-b \right ) a^{2}+\left (-b^{2}-2 c_{1} \right ) a +b^{2} x^{2}}{2 a^{2} b}}+b \left (-x^{2}+a \right )\right )}}{a} \\ \end{align*}

Solution by Mathematica

Time used: 60.984 (sec). Leaf size: 178

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

\begin{align*} y(x)\to -\frac {\sqrt {b} \sqrt {(a+b) \left (a-x^2\right )+2 a^2 W\left (\frac {c_1 (a+b) \exp \left (-\frac {(a+b) \left (a \left (b+x^2\right )-b x^2\right )}{2 a^2 b}\right )}{2 a^3 b^2}\right )}}{\sqrt {a} \sqrt {a+b}} \\ y(x)\to \frac {\sqrt {b} \sqrt {(a+b) \left (a-x^2\right )+2 a^2 W\left (\frac {c_1 (a+b) \exp \left (-\frac {(a+b) \left (a \left (b+x^2\right )-b x^2\right )}{2 a^2 b}\right )}{2 a^3 b^2}\right )}}{\sqrt {a} \sqrt {a+b}} \\ \end{align*}