Find k
Source: China TST 2004 Quiz
February 1, 2009
inequalities unsolvedinequalities
Problem Statement
Find the largest positive real , such that for any positive reals , there is always:
(a\plus{}b\plus{}c) \left[ 3^4(a\plus{}b\plus{}c\plus{}d)^5 \plus{} 2^4(a\plus{}b\plus{}c\plus{}2d)^5 \right] \geq kabcd^3