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Re: Maxima, Minima and Inequalities- The Basics
by rizwanur rahman - Monday, 12 October 2015, 05:05 PM
  Given , a*b >= a^3 + b^3

A.p >= G.P

a+b/2 >= (a*b)^1/2

a*b= 4(a^3 + b^3)
a+b >= 4(a^2 + b^2 -ab)

Let a=b

2b>= 4b^2

b(1-2b)>= 0

so b = 1/2
As only non negative numbers are to be considered b=1/2 =a
So., a+b = 1