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Re: Re: Limits of multi-var. functions


Jens-Peer Kuska <kuska at informatik.uni-leipzig.de> wrote:

> Limit[Limit[x^2 y^2 - 2x y^5 + 3y, x -> 2], y -> 3]
> 
> works fine.

To which it must be added that this works *only* in cases where one 
already knows that there is a limit.  Compare

     Limit[Limit[ x y /(x^2 +y^2), x -> 0], y -> 0]

Unfortunately, Limit[ x y /(x^2 + y^2), (x, y) -> (0, 0)] does not
exist, as is easily seen by transforming to polar coordinates.

--Lou Talman


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