设f(x)在x=a处可导,则|f(x)|在x=a处不可导的充分必要条件是( ).
A: f(a)=0,f'(a)=0.
B: f(a)=0,f'(a)≠0.
C: f(a)≠0,f'(a)=0.
D: f(a)≠0,f'(a)≠0.
A: f(a)=0,f'(a)=0.
B: f(a)=0,f'(a)≠0.
C: f(a)≠0,f'(a)=0.
D: f(a)≠0,f'(a)≠0.
举一反三
- 设f(x)在x=n处可导,则|f(x)|在x=a处不可导的充要条件是 . A: f(A) =0,_f’(A) =0. B: f’(A) =0,f’(A) ≠0. C: f(A) ≠0,f(A) =0. D: f(A) ≠0,f’(A) ≠0.
- 设函数f(x)在x=a处可导,则函数|f(x)|在x=a处不可导的充分条件是______ A: f(a)=0且f’(a)=0. B: f(a)=0且f’(a)≠0. C: f(a)>0且f’(a)>0. D: f(a)<0且f’(a)<0.
- 设f(x)在x=n处可导,则|f(x)|在x=a处不可导的充要条件是 ( ). A: f(A) =0,_f'(A) =0. B: f'(A) =0,f C: f(A) ≠0,f(A D: f(A) ≠0,f'(A
- 设f(x)=f(-x),x∈(-∞,+∞),且在(0,+∞)内,f'(x)>0,f"(x)>0,则f(x)在(-∞,0)内必有 A: f'(x)>0,f'(x)>0. B: f'(x)>0,f"(x)<0. C: f'(x)<0,f"(x)<0. D: f'(x)<0,f"(x)>0.
- 设函数f(χ)在点χ-a处可导,则函数|f(χ)|在点χ=a处不可导的充分条件是: 【 】 A: f(a)=0且f′(a)=0. B: f(a)=0,且f′(a)≠0. C: f(a)>0,f′(a)>0. D: f(a)<0,且f′(a)<0.