f(x)

SoNYDvDPro

If F(x^2 + y^2 ) = F(x^2 - y^2 ) + f(2xy)
So Find F(x) =? (|R)

**Posted:** Thu Dec 20, 2007 9:22 am

pbornsztein

I think that $f$ is $F$ , am I wrong? Wink

Pierre.

**Posted:** Thu Dec 20, 2007 10:50 am

BaBaK Ghalebi

you posted the same problem here http://www.artofproblemsolving.com/Forum/viewtopic.php?t=172054 (in persian),I gave a solution there and ehsan2004 gave a link http://www.artofproblemsolving.com/Forum/viewtopic.php?highlight=cauchy&t=51585 (in english)...

now you're posting it again in another forum,why!? Huh?

**Posted:** Thu Dec 20, 2007 12:08 pm

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