Re: Re: Limits of multi-var. functions
- To: mathgroup at smc.vnet.net
- Subject: [mg19893] Re: [mg19838] Re: Limits of multi-var. functions
- From: me at talmanl1.mscd.edu
- Date: Sun, 19 Sep 1999 18:47:39 -0400
- Sender: owner-wri-mathgroup at wolfram.com
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