Question

下列函數(shù)中，圖象經(jīng)過平移或翻折后不能與函數(shù)y=2^x圖象重合的是

A.y=log₂x              B.y=log₂8x             C.y=log₂               D.y=

Answer 1

D?

解析:A.y=2^x關(guān)于y=x的對(duì)稱函數(shù)為y=log₂x,

B.y=log₂8x=3+log₂x,y=2^x關(guān)于y=x對(duì)稱，再向上平移3個(gè)單位即可.

C.y=log₂=-log₂x,y=2^x關(guān)于y=x對(duì)稱，再關(guān)于x軸對(duì)稱即可.?

D.y==2^2x-1,y=2^x向右平移一個(gè)單位，再把橫坐標(biāo)縮短到原來的倍，∴選D.