Thank you, I just back home, 乱弹is senior Mathematician

来源: 于 2010-09-09 19:32:06 [旧帖] [给我悄悄话] 本文已被阅读：次

He got it. I only explain his last inequality.We draw two lines from (x,g(x)) to (y,g(y))and (x,h(x)) to (y,h(y))...easy to get answer.