15.23 problem 431

15.23.1 Maple step by step solution

Internal problem ID [3685]
Internal file name [OUTPUT/3178_Sunday_June_05_2022_08_54_53_AM_33916403/index.tex]

Book: Ordinary differential equations and their solutions. By George Moseley Murphy. 1960
Section: Various 15
Problem number: 431.
ODE order: 1.
ODE degree: 1.

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

Maple gives the following as the ode type

[NONE]

Unable to solve or complete the solution.

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

15.23.1 Maple step by step solution

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

Maple trace

`Methods for first order ODEs: 
--- Trying classification methods --- 
trying homogeneous types: 
differential order: 1; looking for linear symmetries 
trying exact 
Looking for potential symmetries 
trying an equivalence to an Abel ODE 
trying 1st order ODE linearizable_by_differentiation 
--- Trying Lie symmetry methods, 1st order --- 
`, `-> Computing symmetries using: way = 3 
`, `-> Computing symmetries using: way = 4 
`, `-> Computing symmetries using: way = 5`[0, f(x^2+y^2)/y]
 

Solution by Maple

Time used: 0.016 (sec). Leaf size: 30

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

\[ \int _{\textit {\_b}}^{y \left (x \right )}\frac {\textit {\_a}}{f \left (\textit {\_a}^{2}+x^{2}\right )}d \textit {\_a} +\int g \left (x \right )d x -c_{1} = 0 \]

Solution by Mathematica

Time used: 0.254 (sec). Leaf size: 95

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

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