【導(dǎo)讀】)12(在實(shí)數(shù)集上是增函數(shù),則()。4.函數(shù))(xf在),(ba和),,(),,(21dcxbax??5.函數(shù))(xf在區(qū)間]3,2[?xfy的遞增區(qū)間是()。6.已知)(xf在實(shí)數(shù)集上是減函數(shù),若0??ba,則下列正確的是()。的圖像經(jīng)過(guò)原點(diǎn),則此函數(shù)的單調(diào)增區(qū)間是___________. ,單調(diào)遞減區(qū)間為。數(shù)a的取值范圍。12.試用函數(shù)單調(diào)性的定義,判斷函數(shù)1()fxxx??