```Date: Sep 30, 2013 4:09 PM
Author: LudovicoVan
Subject: Re: Is (t^2-9)/(t-3) defined at t=3?

"Julio Di Egidio" <julio@diegidio.name> wrote in message news:l2ckfj\$m9s\$1@dont-email.me...> "Virgil" <virgil@ligriv.com> wrote in message > news:virgil-523099.13365230092013@BIGNEWS.USENETMONSTER.COM...>> In article <l2bb8m\$3gt\$1@dont-email.me>,>> Robin Chapman <R.J.Chapman@ex.ac.uk> wrote:>>> On 30/09/2013 07:58, Ciekaw wrote:>>> > On Saturday, September 28, 2013 6:30:42 PM UTC+2, Hetware wrote:>>> >   >>>> >> But F(t) is not defined at t=3 because it evaluates to 0/0.>>> >>>> > Hint  L'HÃ´pital's rule>>> >>>> > f(t)=t-3>>> > f'(t)=1>>> >>>> > lim[f(t)/f(t)]=lim[f'(t)/f'(t)]=lim[1/1]=1>>> >>>> > Analogy:>>> > If x=0 then sin(x)/x = 1>>>>>> Hetware: 0/0 = 3>>>>>> Ciekaw: 0/0 = 1>>>>>> Any more entrants?>>>> How about 0/0 = NAN ?>> 0/0 = |R, i.e. the entire real line, in closed interval arithmetic.That is incorrect: 0/0 = |R*, i.e. the entire *extended* real line, in closed interval arithmetic.  I think it could be the negative or positive half of it if one considers signed zeros, but I barely remember the details right now.Julio
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