logarit 1) bxba a x log =⇔= ( a,b >0; a≠ 1). 2) ba b a = log . 3) ba b a = log b m b bb bb b b bbbb a a a aa aaa aaa a a m log 1 log)9 loglog)8 logloglog)7 loglog)(log)6 1log)5 01log)4 21 2 1 2121 = = −= += = = α α a b a b b b n b b a c c a a n a log 1 log)12 log log log)11 log 1 log)10 = = = b b bb bbb aa e log 1 log)15 lnlog)14 loglglog)13 10 −= = == Luü thõa Cho a>0; m,n ∈R ta cã: m m m mmm n m nm nmnm n n b a b a baab a a a aaa a a a =       = = = = = − + − )6 ))(5 )4 .)3 1)2 1 )1 0 ( ) mn n m aa = )7 n n n m n m nm nm aa aa nmaaa nmaaa 1 )11 )10 ;10)9 ;1)8 = = <⇔><< >⇔>> Lª ThÞ Ngäc Thuý- Ngocthuygvthpt@gmail.com.vn . logarit 1) bxba a x log =⇔= ( a,b >0; a≠ 1). 2) ba b a = log . 3) ba b a