回复：谢谢您给我打气,

来源: wxcfan123 于 2011-07-15 14:13:18 [] [旧帖] [给我悄悄话] 阅读数 : (234 bytes)
回答: 谢谢您给我打气, 由 jinjing 于 2011-07-15 11:13:27

From "5 is the only root of f(f(x))" to "f(x)= a(x-5)^5 + b" is sup cool. But only genius could jump to there immediately. For general people, like me, the natual conclusion is

f(f(x)) = a(x-5)^2(x^2+bx+c). or a(x-5)^4.

请您先登陆，再发跟帖！