15 设f(a)存在,f(a)neq0.则lim_(xto a)[(1)/(f(a)(x-a))-(1)/(f(x)-f(a))]=____.15 设$f''(
18.-|||-设 =f(ln x), 且 (0)=f(0)=1, 则 ^n(1)=()-|||-A 0-|||-B 1-|||-C -1-|||-D 2
设函数f(x)具有2阶导数,且f(0)=f(1),|f(x)|leq1。证明:(1) 当xin(0,1)时,|f(x)-f(0)(1-x)-f(1)x|leq(
dfrac (1)(2)f(0)
3、若f(x)=f(-x),且在[0,+∞)内f(x)>0,f(x)>0,则在(-∞,0)内必有( )A. f'(x)0,f''(x)0,f''(x)>0
14.设f(x)在闭区间[0,2]上二阶可导,且f(0)=0,f(1)=1,f(2)=-1,证明:至少存在一点ξ∈(0,2),使得f(ξ)+2ξf(ξ)+ξf(
(B)对任意x,f(-x)<0.(C)对任意x,f(-x)>0. (D)对任意x,f(-x)≥0.1.设f(x)在(-∞,+∞)内可导,且对任意$x_{1},x
dfrac (1)(3)f(x) C. -3f(x) D. -dfrac (1)(3)f(x)
6、单选-|||-f-|||-A .lim _(harrow 0)dfrac (f({x)_(0)+5h)-f((x)_(0)+2h)}(h)=f((x)_(0
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.