Subject: Another rewriting question (with exp(%i*%pi*n))
From: Stavros Macrakis
Date: Thu, 23 May 2013 09:45:10 -0400
On Thu, May 23, 2013 at 7:31 AM, Rupert Swarbrick <rswarbrick at gmail.com>wrote:
> exp(%i*n*2*%pi + %i*%pi*x)
The %emode simplifications are pretty simple-minded, it seems. In
particular, ex: exp(2*n*%pi*%i), where n is declared integer, doesn't
simplify, though its rectform does.
Here's one simple trick that might help:
declare(n,integer)$
ex: exp(%i*n*2*%pi + %i*%pi*x)$
subst(xj=x/%i,ratsimp(exponentialize(subst(x=xj*%i,demoivre(ex)))));
The ratsimp may (or may not) change the form of your expression in ways you
don't want, though.
-s