Second derivatives
- To: mathgroup at smc.vnet.net
- Subject: [mg128516] Second derivatives
- From: Bruce McGough <bruce.mcgough at gmail.com>
- Date: Fri, 26 Oct 2012 23:47:51 -0400 (EDT)
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According to the documentation, D[f,{list,n}) should give the n-th order tensor capturing the corresponding Taylor coefficient. This doesn't seem to work in the following example:
G[x_] := F[h[x]];
D[G[{x1, x2}], {{x1, x2}, 2}]
The correct answer is given by
D[D[G[{x1, x2}], {{x1, x2}}], {{x1, x2}}]
Note that for an "abstract function H,
D[H[{x1, x2}], {{x1, x2}, 2}] = D[D[H[{x1, x2}], {{x1, x2}}], {{x1, x2}}]
Any explanation would be very helpful.