感觉51,52皆可用1.确定f(0), 2. 用x,-x和x,x和2x,-x来代替x,y以求得f(x)

来源: 2014-10-13 12:04:03 [旧帖] [给我悄悄话] 本文已被阅读:
f(x)=0, or f(x)=1,or f(x)=-1