154 设 lim _(xarrow {x)_(0)^+}f'(x)=lim _(xarrow {x)_(0)^-}(x)=a, 则-|||-(A)f(x)在 =(x)_(0) 处必可导且 '((x)_(0))=a.-|||-(B)f(x)在 =(x)_(0) 处必连续,但未必可导.-|||-(C)f(x)在 =(x)_(0) 处必有极限但未必连续.-|||-(D)以上结论都不对.

设 函数 f ( x ) 在 x = 0 处可导，且lim _(xarrow 0)dfrac (f(2x)-f(0))(ln (1+3x))=1，则f(0)=(

设y=f(x) 在x0处可导,且 ((x)_(0))=2, 则lim _(xarrow 0)dfrac (f({x)_(0)+2)x-f((x)_(0)-f(x

1．设f(x)在x=0处可导，且f(0)=0,则lim _(xarrow 0)dfrac (f(3x)-f(x))(x)-|||-__=______.1．设f(

1.若f(x)在 x=0 处可导,且 (0)=0, 则 lim _(xarrow 0)dfrac (f(x))(x)= __

设 函数 f ( x ) 在 x = 1 处可导且lim _(xarrow 0)dfrac (f(1)-f(1-x))(2x)=1则 lim _(xarrow

设f(x)的导数在 x=0 处连续,且 lim _(xarrow 0)dfrac (f(x))(x)=3, 则 x=0 () .-|||-(A)是f(x)的极小

(2)设函数f(x)在区间 (-1,1) 内有定义,且 lim _(xarrow 0)f(x)=0, 则-|||-(A)当 lim _(xarrow 0)dfr

[题目]-|||-设 ((x)_(0))=3 则 lim _(xarrow 0)dfrac (f({x)_(0)+x)-f((x)_(0)-3x)}(x)= _

若函数f(x)在 x=0 处连续,且 lim _(xarrow 0)dfrac (f(x))(x) 存在,证明 f(x)在 x=0 处可导.

(B)若 lim _(xarrow 0)dfrac (f(x)+f(-x))(x) 存在,则 (0)=0.-|||-(C)若 lim _(xarrow 0)df