Re: How to find out the transformation used in Mathematica
- To: mathgroup at smc.vnet.net
- Subject: [mg51470] Re: How to find out the transformation used in Mathematica
- From: Ann Lee <kan2 at rogers.com>
- Date: Tue, 19 Oct 2004 02:55:42 -0400 (EDT)
- References: <ckt7jn$7cv$1@smc.vnet.net> <ckv8a1$i6t$1@smc.vnet.net>
- Reply-to: kan2 at rogers.com
- Sender: owner-wri-mathgroup at wolfram.com
Hi
Thanks, but that does not solve my problem. Exactly what kind
of transformation that we need to make in order to arrive at the
formula in Abramowitz and Stegun?
Best,
Ann
On Mon, 18 Oct 2004 02:03:45 +0000 (UTC), carlos at colorado.edu (Carlos
Felippa) wrote:
>Ann Lee <kan2 at rogers.com> wrote in message news:<ckt7jn$7cv$1 at smc.vnet.net>...
>> Hi,
>>
>> I tried the following indefinite integral
>>
>> Integrate[Exp[-x^2/2]/(4 + x^2), {x, -Infinity, Infinity}]
>>
>> Mathematica gave me
>>
>> Pi*e^2*Erfc[Sqrt[2]]
>>
>> which is very nice. However, I don't know how Mathematica got
>> this answer and would like to find out what kind of transformation
>> that it uses to get this answer. Is there anyway for us to ask
>> Mathematica to provide the transformation that it uses to arrive at
>> this answer. Or alternatively, can anyone tell me how to get the
>> integral above?
>>
>>
>> Best,
>>
>> Ann
>
>
>Storing tables is one way. That integral is 7.4.11 of Abramowitz and
>Stegun (1964)
>
>Some tables, e.g. Gradshteyn, now come in cdrom with the results
>typeset-ready for cut & paste in TeX.