IMO 2019 Shortlist A1
Let Z be the set of integers. Determine all functions f : Z Ñ Z such that, for all integers a and b, fp2aq 2fpbq “ fpfpa...
Category: Algebra
Problem
Let Z be the set of integers. Determine all functions f : Z Ñ Z such that, for all
integers a and b,
fp2aq 2fpbq “ fpfpa bqq.
(South Africa)