Chinese TST 2008 P6
Source:
April 3, 2008
inequalitiesgeometric sequencealgebra proposedalgebra
Problem Statement
Find the maximal constant , such that for arbitrary integer there exist two sequences of positive real number and satisfying
(1): \sum_{k \equal{} 1}^{n}b_{k} \equal{} 1,2b_{k}\geq b_{k \minus{} 1} \plus{} b_{k \plus{} 1},k \equal{} 2,3,\cdots,n \minus{} 1;
(2): a_{k}^2\leq 1 \plus{} \sum_{i \equal{} 1}^{k}a_{i}b_{i},k \equal{} 1,2,3,\cdots,n, a_{n}\equiv M.