题目内容
A.x4+1 B.(x-1)4 C.x4 D.(x+1)4
设S=(x-1)4+4(x-1)3+6(x-1)2+4(x-1)+1,则S等于( )
A.{1,2,4} B.{1,2,3,4,5,7} C.{1,2} D.{1,2,4,5,6,8}