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Re: Best syntax for derivative

  • To: mathgroup at smc.vnet.net
  • Subject: [mg96460] Re: Best syntax for derivative
  • From: Alexei Boulbitch <Alexei.Boulbitch at iee.lu>
  • Date: Sat, 14 Feb 2009 03:07:59 -0500 (EST)

Like this?

In[41]:=   g[x_, y_, z_] := D[Sin[x y z], y];
                g[x, y, z]

Out[42]=  x z Cos[x y z]

or like this?

In[43]:= g[x_, y_, z_] := \!\(
\*SubscriptBox[\(\[PartialD]\), \(y\)]\ \(Sin[x\ y\ z]\)\);
g[x, y, z]

Out[44]= x z Cos[x y z]

??


Hi,

Suppose I have a function of three variables

f[x_, y_, z_]:=Sin[x y z]

And I want to construct g[x, y, z] which is the partial derivative of f
[] with respect to y. I do

f[x_, y_, z_] := Sin[x y z]
g[x_, y_, z_] := D[f[x, temp, z], temp] /. temp -> y

but I'm sure there is something better. Something along the lines of

g = Partial[f, 2]

Many thanks in advance.

Aaron



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