MathDB
2013 Japan Mathematical Olympiad Finals Problem 2

Source:

February 11, 2013
functioninductionalgebra proposedalgebra

Problem Statement

Find all functions f:ZRf:\mathbb{Z}\rightarrow\mathbb{R} such that the equality f(m)+f(n)=f(mn)+f(m+n+mn)f(m)+f(n)=f(mn)+f(m+n+mn) holds for all m,nZ.m,n\in\mathbb{Z}.