【正文】
)作差:(3)變形:(4)判斷差的符號(hào):(5)下結(jié)論練習(xí):(1)證明函數(shù)在R上是增函數(shù)(2)求證函數(shù)上是減函數(shù),在上是增函數(shù)考點(diǎn)2:求函數(shù)的單調(diào)區(qū)間①利用圖像求函數(shù)的單調(diào)區(qū)間例2:畫出函數(shù)的圖像,并指出函數(shù)的單調(diào)區(qū)間??键c(diǎn)3:利用函數(shù)的單調(diào)性求函數(shù)的最值例6:已知函數(shù),求當(dāng)時(shí)的值域。變式:已知函數(shù)是定義在上的單調(diào)增函數(shù),不等式的x的取值范圍是( )A. B. C. D. 。變式:(1)已知函數(shù),求實(shí)數(shù)a的取值范圍,使在區(qū)間上是單調(diào)函數(shù).(2) 求函數(shù)的最大值(3) 已知.