A.10%                            B.9%

C.11%                            D.%

A.(0,10)                            B.(0,5)

C.(5,10)                            D.(-∞,10)

A.10%                                B.16.5%

C.16.8%                             D.20%

A.y=2^x                                              B.y=2x(x∈N^*)

C.y=2^x(x∈N^*)                                   D.y=log₂x

(1)写出函数f(x)的单调区间,并加以证明;

(2)若方程4^a-m·2^a+1+5=0有两个不相等的实根,求m的取值范围.

A.y=(x+1)                       B.y=log₂

C.y=log₃                             D.y=(x²-4x+5)