【導(dǎo)讀】U=R,A={x|x≤0},函數(shù)1yx??Ay軸對(duì)稱B直線yx?對(duì)稱C坐標(biāo)原點(diǎn)對(duì)稱D直線yx??的所有集合M的個(gè)數(shù)是。恒成立,則實(shí)數(shù)a的取值范圍是。上是增函數(shù),且fafa???求函數(shù)()fx的定義域和值域;判斷函數(shù)()fx在區(qū)間(2,5)上單調(diào)性,并用定義來證明所得結(jié)論.yfx的單調(diào)增區(qū)間;若對(duì)任意的實(shí)數(shù)13[,]22?