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Guest
Posted: Mon Dec 18, 2006 3:49 am
Hey, my flat-mates left this problem on the fridge, and its driving me
nuts! (game we play...)

Let f be an entire function such that Re(f(z))+Im(f(z)) < 1 for all z.
Show that f is constant.

So far, I've got that f is holomorphic and entire...

Thanks for any help!
Robert Israel
Posted: Mon Dec 18, 2006 3:51 pm
Guest
In article <1166428150.098160.284810@79g2000cws.googlegroups.com>,
<bensaou@gmail.com> wrote:
Quote:
Hey, my flat-mates left this problem on the fridge, and its driving me
nuts! (game we play...)

Let f be an entire function such that Re(f(z))+Im(f(z)) < 1 for all z.
Show that f is constant.

So far, I've got that f is holomorphic and entire...

Thanks for any help!

Hint: Apply a fractional linear transformation and then use
Liouville's Theorem.

Robert Israel israel@math.ubc.ca
Department of Mathematics http://www.math.ubc.ca/~israel
University of British Columbia Vancouver, BC, Canada
 
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