RE: non zero result after multiplying with zero.

*To*: mathgroup at smc.vnet.net*Subject*: [mg36442] RE: [mg36420] non zero result after multiplying with zero.*From*: "Wolf, Hartmut" <Hartmut.Wolf at t-systems.com>*Date*: Sat, 7 Sep 2002 02:53:53 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

>-----Original Message----- >From: rajgupta121 at rediffmail.com [mailto:rajgupta121 at rediffmail.com] To: mathgroup at smc.vnet.net >Sent: Friday, September 06, 2002 9:17 AM >Subject: [mg36442] [mg36420] non zero result after multiplying with zero. > > >Hi everybody, > > When I multiply an expression with 0 it is giving 0.expression which >is creating problem in the further calculation. > >eg. > >In[1]:=func1[r_]:=Exp[-r/2] >In[2]:coeff[[1,1]]=0.0; >; >; >In[34]:=func1[r]coeff[[1,1]] > >Out[34]:=0.Exp[-r/2] > >I want anything to be multiply by zero must be zero. > > How can I do that? >Your suggestion will be highly appreciated. > > Thanks in advance, > > Raj > Raj, this simply is, because 0. Exp[-r/2] is not always zero! func1[-Infinity]coeff[[1, 1]] >From In[90]:= Infinity::"indet": "Indeterminate expression 0. Infinity encountered." Out[90]= Indeterminate -- Hartmut Wolf