選D
y = 2^x 增函數(shù)
y = log2(1/2)^2 是常數(shù)
y = x^-1 （-∞,0）減函數(shù),（0,+∞）增函數(shù)
y = 2^log2^x = 2^(x * log2) 增函數(shù)
選A
M = {y|y = 2^x} = {y|y > 0}
N = {y|y = log2^x} = {y|y = xlog2 ∈ R}
M包含于N,M是N的子集,M交N=M
選A
滿足f(x + y) = f(x)f(y)形式的函數(shù),一般是指數(shù)函數(shù)a^(x + y) = a^x * a^y
補(bǔ)充說明一下：
對數(shù)函數(shù)y = logax 滿足f(xy) = f(x) + f(y)
冪函數(shù)y = x^a 滿足f(xy) = f(x)f(y)
正比例函數(shù)y = ax 滿足f(x + y) = f(x) + f(y)