24.20 problem 682

24.20.1 Maple step by step solution

Internal problem ID [3929]
Internal file name [OUTPUT/3422_Sunday_June_05_2022_09_18_14_AM_39052743/index.tex]

Book: Ordinary differential equations and their solutions. By George Moseley Murphy. 1960
Section: Various 24
Problem number: 682.
ODE order: 1.
ODE degree: 1.

The type(s) of ODE detected by this program : "unknown"

Maple gives the following as the ode type

[_rational]

Unable to solve or complete the solution.

\[ \boxed {\left (a -3 x^{2}-y^{2}\right ) y y^{\prime }+x \left (a -x^{2}+y^{2}\right )=0} \] Unable to determine ODE type.

24.20.1 Maple step by step solution

\[ \begin {array}{lll} & {} & \textrm {Let's solve}\hspace {3pt} \\ {} & {} & \left (a -3 x^{2}-y^{2}\right ) y y^{\prime }+x \left (a -x^{2}+y^{2}\right )=0 \\ \bullet & {} & \textrm {Highest derivative means the order of the ODE is}\hspace {3pt} 1 \\ {} & {} & y^{\prime } \\ \bullet & {} & \textrm {Solve for the highest derivative}\hspace {3pt} \\ {} & {} & y^{\prime }=-\frac {x \left (a -x^{2}+y^{2}\right )}{\left (a -3 x^{2}-y^{2}\right ) y} \end {array} \]

Maple trace

`Methods for first order ODEs: 
--- Trying classification methods --- 
trying a quadrature 
trying 1st order linear 
trying Bernoulli 
trying separable 
trying inverse linear 
trying homogeneous types: 
trying Chini 
differential order: 1; looking for linear symmetries 
trying exact 
Looking for potential symmetries 
trying inverse_Riccati 
trying an equivalence to an Abel ODE 
differential order: 1; trying a linearization to 2nd order 
--- trying a change of variables {x -> y(x), y(x) -> x} 
differential order: 1; trying a linearization to 2nd order 
trying 1st order ODE linearizable_by_differentiation 
--- Trying Lie symmetry methods, 1st order --- 
`, `-> Computing symmetries using: way = 2`[0, (x^4+2*x^2*y^2+y^4)/(-3*x^2-y^2+a)/y]
 

Solution by Maple

Time used: 0.016 (sec). Leaf size: 122

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

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

Solution by Mathematica

Time used: 0.336 (sec). Leaf size: 39

DSolve[(a-3*x^2-y[x]^2)*y[x]*y'[x]+x*(a-x^2+y[x]^2)==0,y[x],x,IncludeSingularSolutions -> True]
 

\[ \text {Solve}\left [\frac {1}{2} \left (\frac {a+2 y(x)^2}{x^2+y(x)^2}+\log \left (x^2+y(x)^2\right )\right )=c_1,y(x)\right ] \]