Asian Pacific Mathematical Olympiad 2010 Problem 5
Source:
May 7, 2010
functionalgebra proposedalgebra
Problem Statement
Find all functions f from the set R of real numbers into R which satisfy for all x,y,z∈R the identity f(f(x)+f(y)+f(z))=f(f(x)−f(y))+f(2xy+f(z))+2f(xz−yz).