江画工太猩院 例5求函数y= log,x(a>0,a≠1)的导数 解y=lim g,(x+ h-log,x h→0 loga(+o) =lim h→0x lim logo (lt"=l 0g已 h-→0 Bp (log, x)'==log e. (Inx)'= x江西理工大学理学院 例5 求函数 y = log x(a > 0,a ≠ 1)的导数. a 解 h x h x y a a h log ( ) log lim0 + − ′ = → log . 1 (log ) e x a x = a 即 ′ . 1 (ln ) x x ′ = x x h x h a h 1 log (1 ) lim 0 ⋅ + = → h x a h x h x lim log (1 ) 1 0 = + → log . 1 e x = a