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Re: Substiuting variables within an integral

• To: mathgroup at smc.vnet.net
• Subject: [mg111383] Re: Substiuting variables within an integral
• From: "Eduardo M. A. M.Mendes" <emammendes at gmail.com>
• Date: Thu, 29 Jul 2010 06:45:53 -0400 (EDT)

Hi Simon

Since I am a newbie I wonder whether you would have a simple example.

Many many thanks

Ed

-----Original Message-----
From: Simon [mailto:simonjtyler at gmail.com] 
Sent: Wednesday, July 28, 2010 3:53 AM
To: mathgroup at smc.vnet.net
Subject: [mg111383] [mg111335] Re: Substiuting variables within an integral

Hi Ed,

You can try working with the integrand and limits with out the
integral.  Something like
f[x] Dt[x] && x0<x<x1
Then using replacement rules should just work.
The total derivative Dt[] assumes that everything is a variable, so if
you have any other parameters floating around you have to give them
the attribute Constant.

You can then get mathematica to check the form of the integrand - if
it matches what you want, then integrate.

Simon

On Jul 27, 6:14 pm, "Eduardo M. A. M.Mendes" <emammen... at gmail.com>
wrote:
> Hello
>
> I need to do a variable substitution within an integral in several
different
> ways. I need Mathematica to rearrange the integral with the new variable
> definition without solving it.   The resulting integral will be variations
> of Euler function.  After seeing the resulting integral, I need
Mathematica
> to actually solve it for me (that is, Mathematica needs to recognize that
it
> is an Euler function).  Can this be done?
>
> Many thanks
>
> Ed