【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I2.6对数与对数函数理INCLUDEPICTURE"E:\\赵丽君2016\\一轮2016\\数学\\苏教（理）\\word\\基础知识自主学习.tif"\*MERGEFORMATINETINCLUDEPICTURE"E:\\赵丽君2016\\一轮2016\\数学\\苏教（理）\\word\\基础知识自主学习.tif"\*MERGEFORMATINETINCLUDEPICTURE"E:\\赵丽君2016\\一轮2016\\数学\\苏教（理）\\word\\基础知识自主学习.tif"\*MERGEFORMATINETINCLUDEPICTURE"E:\\赵丽君2016\\一轮2016\\数学\\苏教（理）\\word\\基础知识自主学习.tif"\*MERGEFORMATINETINCLUDEPICTURE"E:\\赵丽君2016\\一轮2016\\数学\\苏教（理）\\word\\基础知识自主学习.tif"\*MERGEFORMATINETINCLUDEPICTURE"E:\\赵丽君2016\\一轮2016\\数学\\苏教（理）\\word\\基础知识自主学习.tif"\*MERGEFORMATINETINCLUDEPICTURE"E:\\赵丽君2016\\一轮2016\\数学\\苏教（理）\\word\\基础知识自主学习.tif"\*MERGEFORMATINETINCLUDEPICTURE"E:\\赵丽君2016\\一轮2016\\数学\\苏教（理）\\word\\基础知识自主学习.tif"\*MERGEFORMATINETINCLUDEPICTURE"E:\\赵丽君2016\\一轮2016\\数学\\苏教（理）\\word\\基础知识自主学习.tif"\*MERGEFORMATINETINCLUDEPICTURE"E:\\赵丽君2016\\一轮2016\\数学\\苏教（理）\\word\\基础知识自主学习.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"\*MERGEFORMATINETINCLUDEPICTURE"E:\\赵丽君2016\\一轮2016\\数学\\苏教（理）\\word\\知识梳1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．对数的概念一般地，如果a(a>0，a≠1)的b次幂等于N，即ab＝N，那么就称b是以a为底N的对数，记作logaN＝b，N叫做真数．2．对数的性质与运算法则(1)对数的运算法则如果a>0且a≠1，M>0，N>0，那么①loga(MN)＝logaM＋logaN；②loga＝logaM－logaN；③logaMn＝nlogaM(n∈R)；④＝logaM(m，n∈R，且m≠0)．(2)对数的性质①＝__N__；②logaaN＝__N__(a>0且a≠1)．(3)对数的重要公式①换底公式：logbN＝(a，b均大于零且不等于1)；②logab＝，推广logab·logbc·logcd＝logad.3．对数函数的图象与性质a>10
