Thread Subject: To Solve Two Equations having Bessel Functions

  
  Selam.
  I've got to create a m-file such that I have two unknowns and two equations: which include Bessel function of the first kind and the modified Bessel function of the second kind and their first derrivatives.

  So, which method can you suggest me to use to solve these two equations? Is there any person who has got an idea?

"?nder " <onderbey_@hotmail.com> wrote in message <h2q3cl$df9$1@fred.mathworks.com>...
>
> Selam.
> I've got to create a m-file such that I have two unknowns and two equations: which include Bessel function of the first kind and the modified Bessel function of the second kind and their first derrivatives.
>
> So, which method can you suggest me to use to solve these two equations? Is there any person who has got an idea?

Use fsolve. Remember, if the bessel functions return complex
arguments, this is really a 4 equation problem.

John

"John D'Errico" <woodchips@rochester.rr.com> wrote in message <h2qbmt$odo$1@fred.mathworks.com>...
> "?nder " <onderbey_@hotmail.com> wrote in message <h2q3cl$df9$1@fred.mathworks.com>...
> >
> > Selam.
> > I've got to create a m-file such that I have two unknowns and two equations: which include Bessel function of the first kind and the modified Bessel function of the second kind and their first derrivatives.
> >
> > So, which method can you suggest me to use to solve these two equations? Is there any person who has got an idea?
>
> Use fsolve. Remember, if the bessel functions return complex
> arguments, this is really a 4 equation problem.
>
> John

Thank you, but tell me what did u mean by saying 'this is really a 4 equation problem' ?

?nder wrote on 05-Jul-09 04:39 :
>
> Selam.
> I've got to create a m-file such that I have two unknowns and two equations: which include Bessel function of the first kind and the modified Bessel function of the second kind and their first derrivatives.
>
> So, which method can you suggest me to use to solve these two equations? Is there any person who has got an idea?

see also: Matlab --> Help --> Search: fzero

"?nder " <onderbey_@hotmail.com> wrote in message <h2upei$t74$1@fred.mathworks.com>...
> "John D'Errico" <woodchips@rochester.rr.com> wrote in message <h2qbmt$odo$1@fred.mathworks.com>...
> > "?nder " <onderbey_@hotmail.com> wrote in message <h2q3cl$df9$1@fred.mathworks.com>...
> > >
> > > Selam.
> > > I've got to create a m-file such that I have two unknowns and two equations: which include Bessel function of the first kind and the modified Bessel function of the second kind and their first derrivatives.
> > >
> > > So, which method can you suggest me to use to solve these two equations? Is there any person who has got an idea?
> >
> > Use fsolve. Remember, if the bessel functions return complex
> > arguments, this is really a 4 equation problem.
> >
> > John
>
> Thank you, but tell me what did u mean by saying 'this is really a 4 equation problem' ?

A complex number is really a two dimensional
thing. It is a PAIR of numbers, (a + bi).

So if you will try to solve the equation f(x) = 0,
where f(x) returns a complex result, then you
have in reality TWO equations, real(f(x)) = 0,
and imag(f(x)) = 0.

Since you have two of these equations, then if
this is a problem with complex results and complex
arguments, then you have a system of 4 equations
in 4 unknowns.

John