Re: Series[] command
- To: mathgroup at smc.vnet.net
- Subject: [mg55951] Re: [mg55939] Series[] command
- From: Bob Hanlon <hanlonr at cox.net>
- Date: Tue, 12 Apr 2005 05:26:00 -0400 (EDT)
- Reply-to: hanlonr at cox.net
- Sender: owner-wri-mathgroup at wolfram.com
They are equal Series[a*b,{a,ma,2},{b,mb,2}]//Normal a (b-mb)+(a-ma) mb+ma mb %//Simplify a b ma*mb+ma(b-mb)+mb(a-ma)+(a-ma)(b-mb)//Simplify a b Bob Hanlon > > From: "Kris Preacher" <preacher at unc.edu> To: mathgroup at smc.vnet.net > Date: 2005/04/10 Sun PM 11:07:18 EDT > To: mathgroup at smc.vnet.net > Subject: [mg55951] [mg55939] Series[] command > > Hi all, > > I need to obtain the second-order Taylor series expansion of a*b around the > points ma and mb. I thought Mathematica's Series[] command would do the > trick, but no. The correct answer is: > > ma*mb + ma(b-mb) + mb(a-ma) + (a-ma)(b-mb) > > Mathematica gives: > > b(a-ma) + ma(b-mb) + ma*mb > > Whaddup?? > > Thanks, > Kris Preacher > UNC > > >