Re: Wrong partial derivatives calculated
- To: mathgroup at smc.vnet.net
- Subject: [mg41192] Re: Wrong partial derivatives calculated
- From: Mark Westwood <MarkCWestwood at compuserve.com>
- Date: Tue, 6 May 2003 06:07:45 -0400 (EDT)
- References: <b9514r$r86$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
David, I get: In[2]:= D[x^2+x y+y^2,x] Out[2]= 2 x+y In[4]:= D[x^2+x y+y^2,y] Out[4]= x+2 y I'm using v4.2.1 on Windows 95. You might want to check: - in your email you have included the term 'xy' which, in Mathematica's syntax, is a symbol with the name 'xy', insert a space if you want to indicate multiplication, as in 'x y'; - have you previously defined x and y ? If so those definitions might be interfering. Regards Mark Westwood 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