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.

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

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 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.没f(x)在 x=0 处连续,则f(x)在 x=0 处可导的充分条件为 ()-|||-(A) lim _(xarrow 0)dfrac (f(x)-f(-x

[题目]已知f((x)在 x=0 处可导,且 (0)=0, 则-|||-lim _(xarrow 0)dfrac ({x)^2f(x)-2f((x)^3)}({

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

[题目]已知f(x)在 x=0 处可导,且 (0)=0, 则-|||-lim _(xarrow 0)dfrac ({x)^2f(x)-2f((x)^3)}({x

154 设 lim _(xarrow {x)_(0)^+}f(x)=lim _(xarrow {x)_(0)^-}(x)=a, 则-|||-(A)f(x)在 =