(1)loga(M.N)=longaM+longaN
(2)longa(M/N)=longaM-longaN
(3)logaM的n次方=nlogaM
(4)logaM的n次开方=logaM的n次方分之一,或=1/nlogaM
(5)loga的n次方M,=1/nlogaM
(6)logaa=1
(7)alogaN=N(a>0且a不等于1,N>0)
(8)logab=logmb/logma(换底公式)
ps
lg10=lg(常用对数)
loge=ln(自然对数)
loga1=0