Failures (?) in Limit[f[x,y],x->x0]
- To: mathgroup at smc.vnet.net
- Subject: [mg34720] Failures (?) in Limit[f[x,y],x->x0]
- From: Jack Goldberg <jackgold at umich.edu>
- Date: Mon, 3 Jun 2002 01:46:38 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Hi Group, Consider this for starters: (1) Limit[ f[x], x->0 ] returns unmodified as it should. (2) Limit[ f[x], x->0, Analytic->True ] returns f[0]. This is what the help menu says should happen and it does. Now, (3) Limit[ f[x,y], x->0 ] returns f[0,y] !!!!! This is bad news for many reasons besides the obvious violation of the definition as given in the Help. It may be wrong if f[x,y] is discontinuous at x = 0. By the way, you can replace 0 by any parameter and write f as any function with 2 or more variables WHICH IS NOT built-in. I have not checked it using built-in functions of more than one variable. I hope I am missing something because my work requires that Limit obey the rules I thought I understood by readin ? Limit . As always, I am grateful for your thoughts and comments. Jack