MathDB
Simple FE on National Contest

Source: INAMO 2023 P2 (OSN 2023)

August 29, 2023
functional equationalgebrafloor functionFloorIndonesia

Problem Statement

Determine all functions f:RRf : \mathbb{R} \to \mathbb{R} such that the following equation holds for every real x,yx,y: f(f(x)+y)=x+f(f(y)). f(f(x) + y) = \lfloor x + f(f(y)) \rfloor. Note: x\lfloor x \rfloor denotes the greatest integer not greater than xx.