【導(dǎo)讀】數(shù)的概念,體會(huì)對(duì)數(shù)函數(shù)是一類重要的函數(shù)模型;○1學(xué)習(xí)指數(shù)函數(shù)時(shí),對(duì)其性質(zhì)研究了哪些內(nèi)容,采取怎樣的方法?注意:○1對(duì)數(shù)函數(shù)的定義與指數(shù)函數(shù)類似,都是形式定義,注意辨別.如:xy2log2?都不是對(duì)數(shù)函數(shù),而只能稱其為對(duì)數(shù)型函數(shù).。○2對(duì)數(shù)函數(shù)對(duì)底數(shù)的限制:0(?函數(shù)圖象都過定點(diǎn)(1,1)11??○3思考底數(shù)a是如何影響函數(shù)xyalog?