f(x + 1/x^2) = f(x) + [f(1/x)]^2
Source: IMO Shortlist 1995, A5
August 10, 2008
functionalgebrafunctional equationIMO Shortlist
Problem Statement
Let be the set of real numbers. Does there exist a function which simultaneously satisfies the following three conditions?(a) There is a positive number such that \minus{} M \leq f(x) \leq M.
(b) The value of is .
(c) If then
f \left(x \plus{} \frac {1}{x^2} \right) \equal{} f(x) \plus{} \left[ f \left(\frac {1}{x} \right) \right]^2