Re: Simple question
- To: mathgroup@smc.vnet.net
- Subject: [mg11270] Re: Simple question
- From: dwcp <dwcp@mail.nerc-essc.ac.uk>
- Date: Wed, 4 Mar 1998 01:39:26 -0500
- Organization: ESSC
- References: <6dg8ro$2vh@smc.vnet.net>
G'day,
Here's an answer and some examples. The key thing is that the dummy
variable f_ (or whatever) can be a function as well as something simple
like a number.
-David.
In[12]:= cleverfunc[f_, x_, n_, p_] := D[f,{x,n}] /. x -> p
In[13]:= cleverfunc[g[z], z, n, p]
(n)
Out[13]= g [p]
In[14]:= cleverfunc[Sin[x^5]/Exp[x y], x, 2, p]
3 5 4 5 8 5 2 5
20 p Cos[p ] 10 p y Cos[p ] 25 p Sin[p ] y Sin[p ]
Out[14]= ------------- - --------------- - ------------- + ----------
p y p y p y p y
E E E E
In[15]:= cleverfunc[Sin[x^5]/Exp[x y], x, 2, 1]
2
20 Cos[1] 10 y Cos[1] 25 Sin[1] y Sin[1] Out[15]=
--------- - ----------- - --------- + ---------
y y y y
E E E E
Anderson Brasil da Silva wrote:
> I am a new user of Mathematica and I am having troubles trying to
> create a function FUNC[f,n,p] that returns the value of the n-th
> derivative of f in the point p.
--
David Pearson, Phone: +44 (0)118 9318741 ESSC,
Fax: +44 (0)118 9316413 University of Reading,
Reading RG6 6AL, Email: dwcp@mail.nerc-essc.ac.uk UK.