# Functional equation $f(x^2+y)=f(x)+f(y^2)$ from Olympiad

Let $f: \mathbb{R} \to \mathbb{R}$ $$f(x^2+y)=f(x)+f(y^2)$$

How do I find all functions that fulfill this equation?

I tried to just write many equalities but it just doesnt help.

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And what is the question about that equation? –  Gerry Myerson Jun 3 '11 at 6:03
You might get a more complete response at  artofproblemsolving.com/Forum/viewforum.php?f=721  where they specialize in contest type problems  –  Will Jagy Jun 3 '11 at 6:06

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