2.68 problem 644

2.68.1 Maple step by step solution

Internal problem ID [8978]
Internal file name [OUTPUT/7913_Monday_June_06_2022_12_54_34_AM_9356481/index.tex]

Book: Differential Gleichungen, E. Kamke, 3rd ed. Chelsea Pub. NY, 1948
Section: Chapter 1, Additional non-linear first order
Problem number: 644.
ODE order: 1.
ODE degree: 1.

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

Maple gives the following as the ode type

[[_1st_order, `_with_symmetry_[F(x),G(x)]`]]

Unable to solve or complete the solution.

\[ \boxed {y^{\prime }+\frac {x^{2} \left (a x -2 \sqrt {a \left (a \,x^{4}+8 y\right )}\right )}{2}=0} \] Unable to determine ODE type.

2.68.1 Maple step by step solution

\[ \begin {array}{lll} & {} & \textrm {Let's solve}\hspace {3pt} \\ {} & {} & y^{\prime }+\frac {x^{2} \left (a x -2 \sqrt {a \left (a \,x^{4}+8 y\right )}\right )}{2}=0 \\ \bullet & {} & \textrm {Highest derivative means the order of the ODE is}\hspace {3pt} 1 \\ {} & {} & y^{\prime } \\ \bullet & {} & \textrm {Solve for the highest derivative}\hspace {3pt} \\ {} & {} & y^{\prime }=-\frac {x^{2} \left (a x -2 \sqrt {a \left (a \,x^{4}+8 y\right )}\right )}{2} \end {array} \]

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 
-> Calling odsolve with the ODE`, diff(diff(y(x), x), x)-2*(diff(y(x), x))/x-(1/2)*(8*x^2-1)*a*x^2, y(x)`   *** Sublevel 2 *** 
   Methods for second order ODEs: 
   --- Trying classification methods --- 
   trying a quadrature 
   trying high order exact linear fully integrable 
   -> Calling odsolve with the ODE`, diff(_b(_a), _a) = (1/2)*(8*_a^5*a-_a^3*a+4*_b(_a))/_a, _b(_a)`      *** Sublevel 3 *** 
      Methods for first order ODEs: 
      --- Trying classification methods --- 
      trying a quadrature 
      trying 1st order linear 
      <- 1st order linear successful 
   <- high order exact linear fully integrable successful 
<- 1st order ODE linearizable_by_differentiation successful`
 

Solution by Maple

Time used: 0.062 (sec). Leaf size: 27

dsolve(diff(y(x),x) = -1/2*x^2*(a*x-2*(a*(a*x^4+8*y(x)))^(1/2)),y(x), singsol=all)
 

\[ c_{1} +\frac {4 x^{3} a}{3}-\sqrt {a \left (x^{4} a +8 y \left (x \right )\right )} = 0 \]

Solution by Mathematica

Time used: 0.535 (sec). Leaf size: 34

DSolve[y'[x] == -1/2*(x^2*(a*x - 2*Sqrt[a*(a*x^4 + 8*y[x])])),y[x],x,IncludeSingularSolutions -> True]
 

\[ y(x)\to \frac {1}{72} a \left (16 x^6-9 x^4-96 c_1 x^3+144 c_1{}^2\right ) \]