simplifcation of (1-x)^a/(x-1) .. simpler example and cure
Subject: simplifcation of (1-x)^a/(x-1) .. simpler example and cure
From: Richard Fateman
Date: Fri, 12 Apr 2013 07:45:50 -0700
On 4/11/2013 5:40 AM, Stavros Macrakis wrote:
> Agreed this is annoying and problematic.
>
> One workaround (which is not really a solution) is
>
> subst(-x,x,ratsimp(subst(-x,x,ex)));
a shorter command: subst(-x,x,ratsubst(-x,x,ex));
Note that the annoyance has a smaller example;
(-m)^a/m.
Though m^a/(-m) is immediately simplified.
Curiously, this is another one of those "system independent bugs".
Mathematica 9.0
does not simplify m^a/(-m)
and FullSimplify[%] leaves it unchanged.
The equivalent substitution trick works in Mathematica, since it too
simplifies m^a/(-m)
by taking the negative sign out of the denominator.
Maple 7 (sorry, I don't have a more recent version) exhibits the same
flaw.