Problem A. 439. (November 2007)
A. 439. Prove that
whenever .
(5 pont)
Deadline expired on December 17, 2007.
Solution. Define also a0=1, and let ,
, and
. We have to prove
.
Applying the Cauchy-Schwarz inequailty on the sequences and
,
Statistics:
6 students sent a solution. 5 points: Lovász László Miklós, Tomon István, Wolosz János. 3 points: 1 student. 0 point: 1 student. Unfair, not evaluated: 1 solutions.
Problems in Mathematics of KöMaL, November 2007