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Bug in Simplify?

  • To: mathgroup at smc.vnet.net
  • Subject: [mg33142] Bug in Simplify?
  • From: adam.smith at hillsdale.edu (Adam Smith)
  • Date: Tue, 5 Mar 2002 03:08:48 -0500 (EST)
  • Sender: owner-wri-mathgroup at wolfram.com

I was recently working with some trig functions.  More specifically
for quantum mechanics where one often has terms like Sin[n Pi].  I
noticed what seemed a bug in Mathematica's Simplify[,Assumptions].

In[1]:=
Simplify[Sin[n*Pi]/n, Element[n,Integers]]

Out[1]=
0

Which is fine as long as n is not zero.

In[2]:=
Limit[Sin[n*Pi]/n, n -> 0]

Out[2]=
Pi

It appears to me that Simplify is correctly determining that Sin[n
Pi]=0 for n an integer, but it ignores the fact that there is an
indeterminate 0/0.  I realize that this is a special case, but it
seems to occur often enough that it should be handled properly or at
least provide a warning message that one should double check the
results.

Am I being picky or do others feel the same?

Adam Smith


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