S2S3优甜 问 2012.06.26

Q1:    If a+b+c=1   and  a>0,b>0,c>0 , prove that  1/a+1/b+1/c >= 9.

Q2:   If  a>0, b>0, c>0, prove that  (a+b+c)^2 > 3(ab+ac+bc).

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