Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
1999
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*November
*December
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 1999

[Date Index] [Thread Index] [Author Index]

Search the Archive

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


  • Prev by Date: Re: Coordinate Transformations
  • Next by Date: Re: Where's the Speed?
  • Previous by thread: Re: Limits of multi-var. functions
  • Next by thread: Re: Limits of multi-var. functions