MathDB

A3

Part of 2021-IMOC qualification

Problems(1)

f(n(f(m)) <= nm

Source: 2021 IMOC qualification problem, A3

12/30/2021
Find all injective function f:N→Nf: N \to N satisfying that for all positive integers m,nm,n, we have: f(n(f(m))≤nmf(n(f(m)) \le nm
functionFunctional inequalityfunctionalinequalitiesalgebra