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Topic: power series problem
Replies: 8   Last Post: Mar 21, 2012 8:13 AM

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Bob Adams

Posts: 55
Registered: 12/13/04
Re: power series problem
Posted: Mar 21, 2012 7:41 AM
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On Mar 21, 7:01 am, Tonico <Tonic...@yahoo.com> wrote:
> On Mar 21, 4:09 am, Robert Adams <robert.ad...@analog.com> wrote:
>

> > Hello
>
> > I am stuck trying to find an expansion for
>
> > f(x) = exp(i*x*log(x))
>
> > i = sqrt(-1), valid for x > 0 (hopefully!).
>
> > Any ideas?
>
> > Thanks!
>
> > Bob
>
> As x is real, x logx is real, and thus f(x) = cos(x logx) + isin(x
> logx) . You can now expand these two functions but not around x = 0,
> as you'll have a problem with log(x) in spite the fact that x logx -->
> 0 when x --> 0+.
>
> Tonio


Thanks, this helps.

Bob



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