【導(dǎo)讀】的b次冪等于N,就是Nab?a叫做對(duì)數(shù)的底數(shù),N叫做真數(shù)。為了簡(jiǎn)便,N的常用對(duì)數(shù)N10log簡(jiǎn)記作lgN。在科學(xué)技術(shù)中常常使用以無(wú)理數(shù)e=……為底的對(duì)數(shù),以e為底的對(duì)數(shù)叫自然對(duì)數(shù)。真數(shù)N的取值范圍:),0(??式化成指數(shù)式,并利用冪的運(yùn)算性質(zhì)進(jìn)行恒等變形;①簡(jiǎn)易語(yǔ)言表達(dá):“積的對(duì)數(shù)=對(duì)數(shù)的和”……