MathDB
easy functional equation

Source: Indonesia IMO 2007 TST, Stage 2, Test 5, Problem 2

November 15, 2009
functionalgebra proposedalgebra

Problem Statement

Find all functions f:Rā†’R f: \mathbb{R} \rightarrow \mathbb{R} satisfying f(f(x \plus{} y)) \equal{} f(x \plus{} y) \plus{} f(x)f(y) \minus{} xy for all real numbers xx and yy.
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