【步步高】（江苏专用）2017版高考数学一轮复习第二章函数概念与基本初等函数I2.2函数的单调性与最值理INCLUDEPICTURE"E:\\赵丽君2016\\一轮2016\\数学\\苏教（理）\\word\\知识梳理.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\赵丽君2016\\一轮2016\\数学\\苏教（理）\\word\\知识梳理.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\赵丽君2016\\一轮2016\\数学\\苏教（理）\\word\\知识梳理.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\赵丽君2016\\一轮2016\\数学\\苏教（理）\\word\\知识梳理.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\赵丽君2016\\一轮2016\\数学\\苏教（理）\\word\\知识梳理.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\赵丽君2016\\一轮2016\\数学\\苏教（理）\\word\\知识梳理.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\赵丽君2016\\一轮2016\\数学\\苏教（理）\\word\\知识梳理.TIF"\*MERGEFORMATINET1．函数的单调性(1)单调函数的定义增函数减函数定义一般地，设函数y＝f(x)的定义域为A，区间I⊆A，如果对于区间I内的任意两个值x1，x2当x1f(x2)，那么就说函数f(x)在区间I上是减函数图象描述INCLUDEPICTURE"E:\\赵丽君2016\\一轮2016\\数学\\苏教（理）\\word\\S20.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\赵丽君2016\\一轮2016\\数学\\苏教（理）\\word\\S20.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\赵丽君2016\\一轮2016\\数学\\苏教（理）\\word\\S20.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\赵丽君2016\\一轮2016\\数学\\苏教（理）\\word\\S20.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\赵丽君2016\\一轮2016\\数学\\苏教（理）\\word\\S20.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\赵丽君INCLUDEPICTURE"E:\\赵丽君2016\\一轮2016\\数学\\苏教（理）\\word\\S21.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\赵丽君2016\\一轮2016\\数学\\苏教（理）\\word\\S21.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\赵丽君2016\\一轮2016\\数学\\苏教（理）\\word\\S21.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\赵丽君2016\\一轮2016\\数学\\苏教（理）\\word\\S21.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\赵丽君2016\\一轮2016\\数学\\苏教（理）\\word\\S21.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\赵丽君12016\\一轮2016\\数学\\苏教（理）\\word\\S20.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\赵丽君2016\\一轮2016\\数学\\苏教（理）\\word\\S20.TIF"\*MERGEFORMATINET自左向右看图象是上升的2016\\一轮2016\\数学\\苏教（理）\\word\\S21.TIF"\*MERGEFORMATINETINCLUDEPICTURE"E:\\赵丽君2016\\一轮2016\\数学\\苏教（理）\\word\\S21.TIF"\*MERGEFORMATINET自左向右看图象是下降的(2)单调区间的定义如果函数y＝f(x)在区间I上是单调增函数或单调减函数，那么就说函数y＝f(x)在区间I上具有单调性，区间I叫做y＝f(x)的单调区间．2．函数的最值前提设函数y＝f(x)的定义域为A，如果存在x0∈A，使得条件对于任意的x∈A，都有f(x)≤f(x0)对于任意的x∈A，都有f(x)≥f(x0)结论f(x0)为最大值f(x0)为最小值【思考辨析】判断下面结论是否正确(请在括号中打“√”或“×”)(1)在增函数与减函数的定义中，可以把“任意两个值x1，x2”改为“存在两个值x1，x2”．(×)(2)对于函数f(x)，x∈D，若x1，x2∈D且(x1－x2)·[f(x1)－f(x2)]>0，则函数f(x)在D上是增函数．(√)(3)函数y＝f(x)在[1，＋∞)上是增函数，则函数的单调递增区间是[1，＋∞)．(×)(4)函数y＝的单调递减区间是(－∞，0)∪(0，＋∞)．(×)(5)所有的单调函数都有最值．(×)(6)对于函数y＝f(x)，若f(1)
