Re: A question on Newton's Method

On Sun, 3 Apr 2005 22:14:07 +0000 (UTC), Roman Werpachowski wrote:
> On the Sun, 3 Apr 2005 15:42:00 -0600, James Van Buskirk wrote:
>>> > f[x_] := x^3-x-1
>>> > fp[x_] := D[f[x],x]
>>> > Plot[fp[x],{x,-1,2}]
>>
>> When you finally figure out how to make this work you will
>> have an excellent example of the true horror of Mathematica!

> f[x_] := x^3 - x - 1
> fp[x_] := D[f[s],s] /. s --> x
> Plot[fp[x],{x, -1, 2}]

> Which is in fact more compatible with the way mathematicians think (a
> mathematician would have written:

> fp(x) := df(s)/ds (x)

I would have written:

f[x_] := x^3 - x - 1
fp = f'
Plot[fp[x],{x,-1,2}]

Which seems much more natural than any of the alternatives so far suggested.



--
Dave Seaman
Judge Yohn's mistakes revealed in Mumia Abu-Jamal ruling.
<http://www.commoncouragepress.com/index.cfm?action=book&bookid=228>
.

Relevant Pages

  • Re: A question on Newtons Method
    ... > have an excellent example of the true horror of Mathematica! ... Roman Werpachowski ... Prev by Date: ...
    (sci.math.num-analysis)
  • Re: A difficult hamiltonian problem
    ... Are there any stable fix points? ... but using Mathematica or Maple this is a very quick ... Prev by Date: ...
    (sci.math)
  • Root condition for polynomials
    ... If it can be done on mathematica what are the ... Regards, ... Terry ... Prev by Date: ...
    (sci.math.num-analysis)
  • Re: Sum of Gaussian functions
    ... To my mind (and with the help of mathematica) the expression ... of this nearly-constant periodic function could be: ... Valeri ... Prev by Date: ...
    (sci.math.num-analysis)
  • Re: macro in other languages
    ... | except Lisp and Scheme? ... Mathematica, somewhat. ... Sebastian Stern ... Prev by Date: ...
    (comp.lang.lisp)