A.F∩G=                                                    B.F=G

C.FG                                                          D.FG

A.y=2lnx(x＞0)                                                B.y=ln(2x)(x＞0)

C.y=lnx(x＞0)                                              D.y=ln(2x)(x＞0)

A.y=和y=()²                                        B.|y|=|x|和y³=x³

C.y=log_ax²和y=2log_ax                                      D.y=x和y=log_aa^x

(1)log₂________log₂；(2)log₃2________1；

(3)log4________0；(4)log₄3________log₃4；

(5)lnπ________ln3.14；(6)log₅6________log₇6.

A.R                                                                B.［－2，+∞)

C.［1，+∞)                                                   D.(0，1)

A.R                                                                B.［0，+∞)

C.［0，6)                                                       D.［0，64)

A.a=2,b=2                                                       B.a=,b=2

C.a=2,b=1                                                       D.a=,b=

A.y=log₅x+1                                                     B.y=log_x5+1

C.y=log₅(x－1)                                                 D.y=log₅x－1

_a

(1)求f(x)的定义域；

(2)求使f(x)＞0的x的取值范围.