Determine f(1/7)
Source: IMO Longlist 1989, Problem 17
September 18, 2008
functionlimitgeometric seriesalgebra unsolvedalgebra
Problem Statement
Let and a continuous function on satisfying f(0) \equal{} 0, f(1) \equal{} 1, and
f \left( \frac{x\plus{}y}{2} \right) \equal{} (1\minus{}a) f(x) \plus{} a f(y) \forall x,y \in [0,1] \text{ with } x \leq y.
Determine