概念三要素的比較：指數(shù)函數(shù)和對(duì)數(shù)函數(shù)都有嚴(yán)格的函數(shù)形式：和，其中底數(shù)都是在且范圍內(nèi)取值的常數(shù)；指數(shù)函數(shù)的指數(shù)就是對(duì)數(shù)函數(shù)的對(duì)數(shù)，由此指數(shù)函數(shù)的定義域和對(duì)數(shù)函數(shù)的值域相同，都是；指數(shù)函數(shù)的冪值就是對(duì)數(shù)函數(shù)的真數(shù)，由此指數(shù)函數(shù)的值域和對(duì)數(shù)函數(shù)的定義域相同，都是。