...[繼續(xù)閱讀]

    一般地,如果一個(gè)數(shù)的n次方等于a(n>1,且n∈N),那么這個(gè)數(shù)叫做a的n次方根.就是說,如果xn＝a,那么x叫做a的n次方根,其中n>1,且n∈N.(1)當(dāng)n是奇數(shù)時(shí),正數(shù)的n次方根是一個(gè)正數(shù),負(fù)數(shù)的n次方根是一個(gè)負(fù)數(shù),這時(shí),a的n次方根用符號(hào)表示.(2)當(dāng)...[繼續(xù)閱讀]

    式子叫做根式,這里n叫做根指數(shù),a叫做被開方數(shù).當(dāng)n為奇數(shù)時(shí),＝a,當(dāng)n為偶數(shù)時(shí),＝|a|....[繼續(xù)閱讀]

    我們規(guī)定正數(shù)的正分?jǐn)?shù)指數(shù)冪的意義是a＝(a>0,m,n∈N,且n>1).正數(shù)的負(fù)分?jǐn)?shù)指數(shù)冪的意義與負(fù)整數(shù)指數(shù)冪的意義相仿,我們規(guī)定a-＝＝(a>0,m,n∈N,且n>1).0的正分?jǐn)?shù)指數(shù)冪等于0,0的負(fù)分?jǐn)?shù)指數(shù)冪沒有意義....[繼續(xù)閱讀]

    如果a(a>0,a≠1)的b次冪等于N,就是ab＝N,那么數(shù)b叫做以a為底N的對(duì)數(shù),記作logaN=b,其中a叫做對(duì)數(shù)的底數(shù),N叫做真數(shù)....[繼續(xù)閱讀]

    ①零和負(fù)數(shù)沒有對(duì)數(shù);②logaa=1;③loga1=0....[繼續(xù)閱讀]

    對(duì)于M>0,N>0,a>0且a≠1,有(1)loga(MN)=logaM+logaN;(2)loga＝logaM-logaN;(3)logaMn＝nlogaM(n∈R)....[繼續(xù)閱讀]

    alogaN＝N(a>0且a≠1,N>0),logbN=(a>0且a≠1,N>0,b>0且b≠1)...[繼續(xù)閱讀]

    以10為底的對(duì)數(shù)log10N叫做常用對(duì)數(shù).通常寫作lgN....[繼續(xù)閱讀]

    以無理數(shù)e=2.718281828…為底的對(duì)數(shù),叫做自然對(duì)數(shù).logeN通常寫作lnN.*...[繼續(xù)閱讀]