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Grad in VectorAnalysis`

• To: mathgroup at smc.vnet.net
• Subject: [mg103822] Grad in VectorAnalysis`
• From: Murray Eisenberg <murray at math.umass.edu>
• Date: Thu, 8 Oct 2009 07:49:55 -0400 (EDT)
• Organization: Mathematics & Statistics, Univ. of Mass./Amherst
• Reply-to: murray at math.umass.edu

After...

   Needs["VectorAnalysis`"]
   SetCoordinates[Cartesian[x, y, z]]

   f[x_, y_] = x/(1 - x^2 - y^2)

... why does the following not actually return the formula for gradient...

   Grad[f[x, y, z]]  (* or even Grad[Evaluate[f[x,y,z]]]

... whereas the following does return it:

   Grad[x/(1 - x^2 - y^2)]



-- 
Murray Eisenberg                     murray at math.umass.edu
Mathematics & Statistics Dept.
Lederle Graduate Research Tower      phone 413 549-1020 (H)
University of Massachusetts                413 545-2859 (W)
710 North Pleasant Street            fax   413 545-1801
Amherst, MA 01003-9305

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