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Re: Limit[f[x], x->a] vs. f[a]. When are they equal?

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  • Subject: [mg118367] Re: Limit[f[x], x->a] vs. f[a]. When are they equal?
  • From: Leonid Shifrin <lshifr at gmail.com>
  • Date: Sun, 24 Apr 2011 08:27:08 -0400 (EDT)

Richard,

On Sat, Apr 23, 2011 at 4:49 AM, Richard Fateman <fateman at cs.berkeley.edu>wrote:

> Let c=ComplexInfinity
>
> then Mathematica (7.0) "knows" that Sin[c] is Indeterminate
>
> but Limit[Sin[x],x->c]  is not evaluated.
>
> I would have thought that if  f[a] is known, Limit[f[x],x->a] is
> also known.
>

Not necessarily. The limiting procedure has nothing to do with the value of
the function at a given point, it has to do with values of the function in
the neighborhood of that point.

Regards,
Leonid


>
> RJF
>
>


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