MathGroup Archive 2010

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Inverse Laplace Transform

  • To: mathgroup at smc.vnet.net
  • Subject: [mg108974] Re: Inverse Laplace Transform
  • From: dh <dh at metrohm.com>
  • Date: Thu, 8 Apr 2010 08:04:54 -0400 (EDT)
  • References: <hphq5p$1hm$1@smc.vnet.net>

On 07.04.2010 13:26, Leslaw Bieniasz wrote:
> Hi,
>
> I need to find an inverse Laplace transform of the
> expression:
>
> Sqrt[s*(s+a)]/(s-b)
>
> where "s" is the Laplace variable, "a" is a real positive constant,
> and "b" is a real constant that can be either positive or negative.
> I have tried the InverseLaplaceTransform[] function, but it
> returns the original expression. My question is: does this mean
> that the inverse transform does not exist, or only Mathematica
> cannot find it?
> Also, if anybody knows where I could possibly find the inverse
> in any book, or how I might obtain the inverse otherwise, I would
> appreciate an information. Abramowitz and Stegun book does not have it.
>
> Leslaw
>

Hi Leslaw,
a conditions for the existence of the inverse Laplace transform of F[s] is:
Limit[F[s],s->Infinity] == 0
this is not the case for your expression.
cheers, Daniel


-- 

Daniel Huber
Metrohm Ltd.
Oberdorfstr. 68
CH-9100 Herisau
Tel. +41 71 353 8585, Fax +41 71 353 8907
E-Mail:<mailto:dh at metrohm.com>
Internet:<http://www.metrohm.com>



  • Prev by Date: Re: Simplifying multiple expressions
  • Next by Date: Re: Speed Up of Calculations on Large Lists
  • Previous by thread: Re: How to enter an integral in a formula and have mathematica *not*
  • Next by thread: Re: Inverse Laplace Transform