MathDB
Miklós Schweitzer 1958- Problem 8

Source:

October 23, 2015
functioncollege contestsMiklos Schweitzer

Problem Statement

8. Let the function f(x)f(x) be periodic with the period 11, non-negative, concave in the interval (0,1)(0,1) and continuous at the point 00. Prove that f(nx)nf(x)f(nx)\leq nf(x) for every real xx and positive integer nn. (R. 6)