2.76 problem 652

2.76.1 Maple step by step solution

Internal problem ID [8986]
Internal file name [OUTPUT/7921_Monday_June_06_2022_12_55_43_AM_31157424/index.tex]

Book: Differential Gleichungen, E. Kamke, 3rd ed. Chelsea Pub. NY, 1948
Section: Chapter 1, Additional non-linear first order
Problem number: 652.
ODE order: 1.
ODE degree: 1.

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

Maple gives the following as the ode type

[`y=_G(x,y')`]

Unable to solve or complete the solution.

\[ \boxed {y^{\prime }-\frac {2 a +x \sqrt {-y^{2}+4 x a}}{y}=0} \] Unable to determine ODE type.

2.76.1 Maple step by step solution

\[ \begin {array}{lll} & {} & \textrm {Let's solve}\hspace {3pt} \\ {} & {} & x \sqrt {-y^{2}+4 x a}-y y^{\prime }+2 a =0 \\ \bullet & {} & \textrm {Highest derivative means the order of the ODE is}\hspace {3pt} 1 \\ {} & {} & y^{\prime } \\ \bullet & {} & \textrm {Solve for the highest derivative}\hspace {3pt} \\ {} & {} & y^{\prime }=-\frac {-2 a -x \sqrt {-y^{2}+4 x a}}{y} \end {array} \]

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 = 5`[0, 1/y*(4*a*x-y^2)^(1/2)], [0, ((4*a*x-y^2)^(1/2)*x^2+8*a*x-2*y^2)/y]
 

Solution by Maple

Time used: 0.0 (sec). Leaf size: 27

dsolve(diff(y(x),x) = (2*a+x*(-y(x)^2+4*a*x)^(1/2))/y(x),y(x), singsol=all)
 

\[ -\sqrt {4 a x -y \left (x \right )^{2}}-\frac {x^{2}}{2}-c_{1} = 0 \]

Solution by Mathematica

Time used: 6.547 (sec). Leaf size: 161

DSolve[y'[x] == (2*a + x*Sqrt[4*a*x - y[x]^2])/y[x],y[x],x,IncludeSingularSolutions -> True]
 

\begin{align*} y(x)\to -\frac {\sqrt {256 a^4 x \left (16 a-x^3\right )+32 a^2 e^{c_1} x^2-e^{2 c_1}}}{32 a^2} \\ y(x)\to \frac {\sqrt {256 a^4 x \left (16 a-x^3\right )+32 a^2 e^{c_1} x^2-e^{2 c_1}}}{32 a^2} \\ y(x)\to -\frac {\sqrt {a^4 x \left (16 a-x^3\right )}}{2 a^2} \\ y(x)\to \frac {\sqrt {a^4 x \left (16 a-x^3\right )}}{2 a^2} \\ \end{align*}