MathDB
find the maximum

Source: 2012 China TST Test 2 p5

March 20, 2012
functioninequalitiesvectorinequalities proposed

Problem Statement

Given two integers m,nm,n which are greater than 11. r,sr,s are two given positive real numbers such that r<sr<s. For all aij0a_{ij}\ge 0 which are not all zeroes,find the maximal value of the expression f=(j=1n(i=1maijs)rs)1r(i=1m)j=1naijr)sr)1s.f=\frac{(\sum_{j=1}^{n}(\sum_{i=1}^{m}a_{ij}^s)^{\frac{r}{s}})^{\frac{1}{r}}}{(\sum_{i=1}^{m})\sum_{j=1}^{n}a_{ij}^r)^{\frac{s}{r}})^{\frac{1}{s}}}.