(2)(uw)'=u'v+uv 证：设f(x)=u(x)v(x),则有 (x)im-()=lim-ux)v(x) h-→0 h h→0 h lim h-→0 x+的国x+)+x+》到 h =u'(x)v(x)+(x)v'(x) 故结论成立 推论：1)(Cu)'=Cu'(C为常数) 2)(uvw)'=u'vw+uv'w+uvw 3)(1og。xy'= Inx Ina xlna OOo⊙⊙8 机元 (2) (uv) = u  v +uv  证: 设 f (x) = u(x)v(x) , 则有 h f x h f x f x h ( ) ( ) ( ) lim 0 + −  = → h u x h v x h u x v x h ( ) ( ) ( ) ( ) lim 0 + + − = → = u (x)v(x) + u(x)v (x) 故结论成立.    + − = → h u x h h ( ) lim 0 u(x) v(x + h)   −  + h v(x) u(x) v(x + h) 推论: 1) (Cu ) = 2) (uvw) = Cu  u  vw+ uv  w+ uvw  3) (loga x ) =        a x ln ln x ln a 1 = 机动 目录 上页 下页 返回 结束 ( C为常数 )