Re: Re: Simplify (-1)^((-1)^n)
- To: mathgroup at smc.vnet.net
- Subject: [mg76503] Re: [mg76453] Re: [mg76401] Simplify (-1)^((-1)^n)
- From: "Lev Bishop" <lev.bishop at gmail.com>
- Date: Wed, 23 May 2007 05:23:07 -0400 (EDT)
- References: <200705220659.CAA20235@smc.vnet.net>
On 5/22/07, Bob Hanlon <hanlonr at cox.net> wrote:
> Applying brute force:
>
> integerSimplify[expr_, n_Symbol]:=Module[{ev,od},
> Off[Simplify::fas];
> ev=Simplify[expr,EvenQ[n]];
> od=Simplify[expr,OddQ[n]];
> On[Simplify::fas];
> If[ev==od,ev,expr]]
>
> integerSimplify[(-1)^((-1)^n),n]
>
> -1
No! That gives wrong answers.
In[65]:= integerSimplify[(-1)^n,n]
Out[65]= 1
You should *never* ignore Simplify::fas or you can prove anything you like:
Eg, pi==3...
In[86]:= Simplify[x==3&&x==\[Pi],False]
During evaluation of In[86]:= Simplify::fas: Warning: One or more
assumptions evaluated to False. >>
Out[86]= True
- References:
- Re: Simplify (-1)^((-1)^n)
- From: Bob Hanlon <hanlonr@cox.net>
- Re: Simplify (-1)^((-1)^n)