Re: how mathematica deals with complex i in output
- To: mathgroup at smc.vnet.net
- Subject: [mg34341] Re: how mathematica deals with complex i in output
- From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
- Date: Thu, 16 May 2002 05:08:22 -0400 (EDT)
- Organization: Universitaet Leipzig
- References: <abt43u$nbp$1@smc.vnet.net>
- Reply-to: kuska at informatik.uni-leipzig.de
- Sender: owner-wri-mathgroup at wolfram.com
Hi,
((I/4)*p^2*Log[1 - (I*Sqrt[a]*(p + qD))/Sqrt[-(a*p^2) -
\[Omega]]])/(a^(3/2)*
Sqrt[-(a*p^2) - \[Omega]]) //.
Power[-a*p^2 - \[Omega], Rational[n_, 2]] :>
I^n*Power[a*p^2 + \[Omega], Rational[n, 2]]
?
Can You please use Omega or omega or w instead
of \[Omega] in a e-mail message ?
Regards
Jens
Nicolas Bock wrote:
>
> Hello,
>
> After integrating an expression, mathematica gave me the following:
>
> (Local) Out[5]//InputForm=
> ((I/4)*p^2*Log[1 - (I*Sqrt[a]*(p + qD))/Sqrt[-(a*p^2) -
> \[Omega]]])/(a^(3/2)*Sqrt[-(a*p^2) - \[Omega]])
>
> Sorry about the somewhat confusing form of this expression, but I
> don't know how to do this better in an email. Anyway, my question is
> this: There are a number of I's in the output, which would make you
> believe that the output is something complex. Upon closer inspection
> though one notices that it is actually not, since all the factors of I
> cancel from this expression, if the definition of I is used, I ==
> sqrt(-1). How can I tell mathematica to do the same and to eliminate
> all those factors of I for me? I already tried a number of things, for
> example RealOnly, ImRe, but so far nothing worked. I guess this is a
> problem of how mathematica formats its output and how it arranges the
> terms in the output, but I don't know how to change that behavior.
>
> Thanks already for any suggestions, nick