NaN vs. Inf

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Laurence Lurio
Laurence Lurio 2011-12-31
Why is
1/0 = Inf
but
[1,0]./[1,0] = [1 NaN]
shouldn't it be [1 Inf]?

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采纳的回答

Image Analyst
Image Analyst 2011-12-31
1/0 is infinity, but 0/0 is not infinity nor is it zero - it's just undefined (NaN).
  1 个评论
Matt Tearle
Matt Tearle 2011-12-31
And if you want to know *why*, think in terms of limits. lim_{x->0} 1/x = infinity. But lim_{x->0} x^2/x = 0, lim_{x->0} x/x = 1, and lim_{x_>0} x/x^2 = infinity. So there's no way to determine what a "0/0" limit might be. Hence, it's undefined (NaN).
Similarly, Inf + Inf = Inf, but Inf - Inf = NaN.

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更多回答（2 个）

Jose Jeremias Caballero
Hi.
[1,0]./[1,0]= [1/1,0/0]=[1,NaN]
  1 个评论
Jan
Jan 2012-1-1
The question is, why 0/0=NaN and not Inf.

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Jose Jeremias Caballero

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