patterns - Maple Help
For the best experience, we recommend viewing online help using Google Chrome or Microsoft Edge.

Online Help

Solving ODEs Matching the Patterns y=G(x,diff(y,x)), x=G(y,diff(y,x)), y=G(diff(y,x)), x=G(diff(y,x)), 0=G(x,diff(y,x)), 0=G(y,diff(y,x))

 

Description

Examples

Description

• 

See Differentialgleichungen, by E. Kamke, p. 30. The technique consists mainly of looking for a parametric solution. Consider, for instance, the case y=G(x,diff(y,x)).

ode := y=G(x,diff(y(x),x));

(1)
  

Choosing the parametrization

para := diff(y(x),x) = t;

(2)

ode1 := subs(para,x=x(t),y=y(t), ode);

(3)
  

From the equations above and using the chain rule  , it is possible to obtain another ODE for  as follows:

ode_draft := diff(x(t),t) = diff(rhs(ode1),t)/t:

ode2 := diff(x(t),t)=solve(ode_draft,diff(x(t),t));

(4)
  

You should therefore solve  for  and determine  by introducing the resulting  in . Note that, when G does not depend on  is a quadrature. ODEs matching the pattern  are solved using the same ideas, and ODEs matching the patterns , or  are just particular cases.

• 

Although any ODE can be attempted using the scheme outlined above, generally speaking, there are four cases which can be better dealt with by looking for a parametric solution; they are:

1. 

2. 

3. 

   (particular case)

4. 

   (particular case)

  

Parametric solutions are available by giving the optional argument 'parametric' to dsolve. By default, when the ODE is of high degree in , dsolve tries the parametric scheme, along with a set of related methods for this type of ODE. However, this scheme may also be of help in some cases in which  can be isolated.

Examples

1) Kamke's ODE 554: y=G(x,y')

(5)

(6)

(7)

(8)

(9)

(10)

(11)

(12)

3) Kamke's ODE 568:  and d'Alembert type (see odeadvisor,dAlembert)

(13)

(14)

(15)

Implicit or explicit answers can be tested using odetest; when there are many answers one can map as follows

(16)

See Also

DEtools

odeadvisor

dsolve

quadrature

linear

separable

Bernoulli

exact

homogeneous

homogeneousB

homogeneousC

homogeneousD

homogeneousG

Chini

Riccati

Abel

Abel2A

Abel2C

rational

Clairaut

dAlembert

sym_implicit

odeadvisor,types

 


Download Help Document