Re: Simplifying Exponents

• To: mathgroup at smc.vnet.net
• Subject: [mg43914] Re: [mg43899] Simplifying Exponents
• From: "Peter Pein" <nospam at spam.no>
• Date: Sat, 11 Oct 2003 01:33:33 -0400 (EDT)
• References: <200310100706.DAA19540@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

```Hi Wes,
I can not reproduce the described behaviour:
In[1]:=
\$Version
a*Exp[I*t*(-4 + x) - I*t*x]//Simplify
Out[1]=
4.0 for Microsoft Windows (July 16, 1999)
Out[2]=
\!\(a\ \[ExponentialE]\^\(\(-4\)\ \[ImaginaryI]\ t\)\)

Maybe some of the symbols you're using look same but aren't. What does
FullForm[expression] display? Or did you use Hold[] somwhere in your code?

Peter Pein, Berlin
petsie at arcAND.de
replace && by || to write to me

----- Original Message -----
From: "wes" <wesh at acm.org>
To: mathgroup at smc.vnet.net
Subject: [mg43914] [mg43899] Simplifying Exponents

> I am trying to generate rows of a determinant for a Hill's DE. To
> do this I generate a series of exponentials of the typical form
>
> a Exp[I t(-4 + x) - I t x]
>
> where the coefficient a and integer 4 vary from term to term. There
> also may be more terms in the exponent.
>
> Mathematica resolutely refuses to simplify the exponents, which in
> the above case would result in
>
> a Exp[-4 I t].
>
> There are several terms which have different extended exponents but
> the same simplified exponents.
>
> To generate the determinant I need to collect all of the terms having
> the same simplified exponent.
>