Question

设函数f(x)在x=a处可导,且lim[f(a+5h)]-f(a-5h)]/2h=1,则f'(a)=

Answer 1

那个极限式可以化为5/2(f'(a)+f'(a))=1,也即5f'(a)=1,f'(a)=1/5;