2

Part of 2019 Regional Olympiad of Mexico Center Zone

Problems(1)

f (x + y) <=f (xy) for x,y reals

Source: Mathematics Regional Olympiad of Mexico Center Zone 2019 P2

Find all functions

f: \mathbb {R} \rightarrow \mathbb {R}

f (x + y) \le f (xy)

for every pair of real

x

y

inequalitiesFunctional inequalityfunctionalalgebra