A.3x2-2x+1 B.3x2+2x+1
C.3x2-2x-1 D.x2-2x+1
C
解法一:f′(x)=[]′
=
=3x2-2x-1.
解法二:∵f(x)=
=(x+1)(x-1)2=x3-x2-x+1,
∴f′(x)=3x2-2x-1.