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Re: expected output from log of negative number
From: |
Jordi Gutiérrez Hermoso |
Subject: |
Re: expected output from log of negative number |
Date: |
Fri, 13 Jun 2008 14:21:19 -0500 |
On 13/06/2008, E. Joshua Rigler <address@hidden> wrote:
> If I type log10(-1), I get a complex number back whose real part is the
> log of the absolute value of the argument, and whose imaginary part is
> always equal to 1.36438. What's more, I get similar behavior with a
> natural log, but the imaginary part is always equal to Pi.
Uhm, do you know about branch cuts? That's just the principal branch
of the logarithm, it is (-pi,pi], placing the cut on the negative
imaginary axis.
If you've never seen complex analysis, this might not make much sense.
- Jordi G. H.