MathDB
IMC 2010, Problem 2, Day 2

Source:

July 27, 2010
inequalitiesinductioninequalities unsolved

Problem Statement

Let a0,a1,,ana_0,a_1,\dots,a_n be positive real numbers such that ak+1ak1a_{k+1}-a_k \geq 1 for all k=0,1,,n1.k=0,1,\dots,n-1. Prove that 1+1a0(1+1a1a0)(1+1ana0)(1+1a0)(1+1a1)(1+1an).1+\frac{1}{a_0} \left( 1+\frac1{a_1-a_0}\right)\cdots\left(1+\frac1{a_n-a_0}\right)\leq \left(1+\frac1{a_0}\right) \left(1+\frac1{a_1}\right)\cdots \left(1+\frac1{a_n}\right).