6、单选-|||-f'-|||-A .lim _(harrow 0)dfrac (f({x)_(0)+5h)-f((x)_(0)+2h)}(h)=f'((x)_(0))-|||-B .lim _(harrow 0)dfrac (f({x)_(0)+h)-f((x)_(0)-h)}(h)=2f'((x)_(0)) .-|||-C .lim _(harrow 0)dfrac (f({x)_(0)+3h)-f((x)_(0))}(h)=f'((x)_(0))-|||-D lim _(harrow 0)dfrac (f({x)_(0)+2h)-f((x)_(0)+3h)}(h)=f'((x)_(0))

(1)若f(x)在 =(x)_(0) 处可导,则 () .-|||-(A) lim _(harrow 0)dfrac (f({x)_(0)+2h)-f((x)_

若极限lim _(harrow 0)dfrac (f({x)_(0)+2h)-f((x)_(0))}(h)=dfrac (1)(2)，则导数值lim _(har

若极限 lim_(h to 0) (f(x_0 + 2h) - f(x_0))/(h) = (1)/(2)，则导数值 f(x_0) = ( )。A. $-\fr

(f(x)在 _{0)=(x)_(0) 处可导,且 lim _(harrow 0)dfrac (f({x)_(0)+2h)-f((x)_(0)-h)}(2h)=

(6)设f(x)在x0处可导,则 lim _(harrow 0)dfrac (f({x)_(0)+h)-f((x)_(0)-h)}(h)= () ;-|||-(

设 f(x) 在点 x_0 的邻域内存在，且 f(x_0) 为极大值，则 lim_(h to 0) (f(x_0 + 2h)- f(x_0))/(h) = (

(2)已知f(x)在 =(x)_(0) 处可导,且有 lim _(harrow 0)dfrac (2h)(f({x)_(0))-f((x)_(0)-4h)}=-

设函数f(x)满足lim _(harrow 0)dfrac (1)(h)[ f(5-dfrac (1)(3)h)-f(5)] =2,则lim _(harrow

C. lim _(xarrow 0)dfrac (f(x))(x) 不存在.-|||-f(0)=0 ^11(0)=2.-|||-D.f(0)是f(x)的极小值.

29 设f(x)是以3为周期的可导函数且是偶函数, f(-2)=-1 ,则-|||-.lim _(harrow 0)dfrac (h)(f(5-2sin h)-