... minh a logc b = blogc a p dng tớnh cht log m x = log m y x = y nờn ta ly logarit c s m dng khỏc v trỏi v chng minh nú bng logarit c s m ca v phi log c ( a logc b ) = log c b.log c a =log c a.log ... yờu cu hc sinh nờu cỏc iu kin cỏc biu thc cú ngha nh: Mu khỏc 0, c s a, b tha < a,b 1, i s ca logarit phi dng) Cho < a , x > 0: logax = y a y = x Vi < a ta cú: a log a n = n ( n > ); log ... > b ỡ ù ờb > ù ù f ( x) > log a b a >1; f ( x) < log a b < a m log a n b = m log...