Re: how to specify something is "real"
- To: mathgroup at smc.vnet.net
- Subject: [mg43180] Re: [mg43161] how to specify something is "real"
- From: Peter Pein <peter1963 at totalise.co.uk>
- Date: Sat, 16 Aug 2003 02:54:01 -0400 (EDT)
- References: <200308150827.EAA18123@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
pgp wrote:
> Hi,
> This is probably a dumb question, but I was trying to use Conjugate[] on an
> expression that contains terms like Cos[x], and mathematica doesn't take it
> for granted that Cos[x] is real, and hence the end result contain lots of
> Conjugate's that can't be reduced.
> Could someone tell me if it's possible to tell mathematica which parts of
> the expressions are supposed to be real, so it'll get rid of all those
> Conjugates?
> Thanks a lot.
> -K
>
Hi "pgp",
if /expr/ is the expression containing all these unwanted conjugates, then
FullSimplify[expr, Im[x]==0] or FullSimplify[expr, Element[x,Reals]] should do
what you want. If you've got more than one real variable - say x,y,t - you can
use Element[{x,y,t},Reals].
Peter
- References:
- how to specify something is "real"
- From: "pgp" <bla@bla.com>
- how to specify something is "real"