MathDB
Function

Source: Iranian National Olympiad (3rd Round) 2002

October 1, 2006
functionlimitalgebra proposedalgebra

Problem Statement

f:RR+f: \mathbb R\longrightarrow\mathbb R^{+} is a non-decreasing function. Prove that there is a point aRa\in\mathbb R that f(a+1f(a))<2f(a)f(a+\frac1{f(a)})<2f(a)