Re: Wrong partial derivatives calculated
- To: mathgroup at smc.vnet.net
- Subject: [mg41164] Re: Wrong partial derivatives calculated
- From: Torben Winther Graversen <immtwg at bohr.gbar.dtu.dk>
- Date: Tue, 6 May 2003 06:00:30 -0400 (EDT)
- References: <b9514r$r86$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
David <david at hushmail.com> 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.
Hi David,
I'm guessing the syntax in your example should have been:
D[x^2 + x y + y^2, x]
The space between x and y is crucial - otherwise, Mathematica
treats it as a third variable called "xy".
Best regards,
Torben