2.求导数举例 (C)=0,(y=-1 2√x 例4求f(x)=√x的导数 解f(x)=m(x+h)-f(x) -lim vx+h h->0 h h→>0 h m = Im h>0h(√x+h+√x)h0√x+h+√x2x 返回 页结束铃首页 上页 返回 下页 结束 铃 解 h x h x h f x h f x f x h h + − = + −  = →0 →0 lim ( ) ( ) 解 ( ) lim 例 例 3 4  求 f (x)= x 的导数 解 h x h x h f x h f x f x h h + − = + −  = →0 →0 lim ( ) ( ) ( ) lim h x h x x h x x h h h 2 1 1 lim ( ) lim 0 0 = + + = + + = → →  h x h x x h x x h h h 2 1 1 lim ( ) lim 0 0 = + + = + + = → →  h x h x x h x x h h h 2 1 1 lim ( ) lim 0 0 = + + = + + = → →  下页 2.求导数举例 (C) =0 2 1 ) 1 ( x x  =−  x x 2 1 ( ) =  1 ( ) −  =     (C) =0 x x  2 1 ) 1 ( x x  =−  x x 2 1 ( ) =  1 ( ) −  =     (C) =0 x x  2 1 ) 1 ( x x  =−  x x 2 1 ( ) =  1 ( ) −  =     x x 