Re: Wrong partial derivatives calculated
- To: mathgroup at smc.vnet.net
- Subject: [mg41163] Re: [mg41131] Wrong partial derivatives calculated
- From: Selwyn Hollis <selwynh at earthlink.net>
- Date: Tue, 6 May 2003 06:00:03 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Think about it: How could Mathematica possibly know that your xy expression is supposed to be x*y instead of a variable named xy? ----- Selwyn Hollis http://www.math.armstrong.edu/faculty/hollis On Monday, May 5, 2003, at 02:40 AM, David wrote: > When I calculate (D[x^2 + xy + y^2, x) mathematica gives me 2y and > when I > calculate D[x^2 + xy + y^2, y) I get 2x. These are wrong answers -- > have I > got the syntax right? I'm trying to find partial derivatives of x^2 + > xy + > y^2 with respect to x and y. > > Thanks, > > David > > > >