Re: Series[log[x], {x, 0, 3}]
- To: mathgroup at smc.vnet.net
- Subject: [mg119124] Re: Series[log[x], {x, 0, 3}]
- From: Murray Eisenberg <murray at math.umass.edu>
- Date: Sun, 22 May 2011 06:56:36 -0400 (EDT)
Mathematica is doing exactly what you asked it to do -- because you
typed a lower-case letter "l" for the log function.
Presumably you want the built-in log function. Like all built-in
functions, its name begins with an upper-case letter, "L". Thus you
really want:
Series[Log[x], {x, 0, 3}]
And, because of the singularity at 0, the output you'll get is (in
InputForm):
SeriesData[x, 0, {Log[x]}, 0, 4, 1]
Of course something like
Series[Log[x], {x, 1, 3}]
gives the expected result.
On 5/21/2011 6:44 AM, Hongyi Zhao wrote:
> Hi all,
>
> I do the following computation within Mathematica:
>
> Series[log[x], {x, 0, 3}]
>
> Then I get:
>
> log[0]+(log^\[Prime])[0] x+1/2 (log^\[Prime]\[Prime])[0] x^2+1/6 (log^(3))
> [0] x^3+O[x]^4
>
> Any hints on this result? The log[0] is illegal in my mind.
>
> Regards.
> --
> .: Hongyi Zhao [ hongyi.zhao AT gmail.com ] Free as in Freedom :.
>
--
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)
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