MathDB
Functional equation !

Source: India TST 2001 Day 3 Problem 2

January 31, 2015
functionalgebrapolynomialalgebra proposed

Problem Statement

Find all functions f ⁣:R+R+f \colon \mathbb{R_{+}}\to \mathbb{R_{+}} satisfying : f(f(x)x)=2xf ( f (x)-x) = 2x for all x>0x > 0.