f(x)在x=1时导数为2 ,limx→0 f{(1-k)-f(1)}/2k=?
问题描述:
f(x)在x=1时导数为2 ,limx→0 f{(1-k)-f(1)}/2k=?
答
limx→0 f{(1-k)-f(1)}/2k
=-1/2 limx→0 f{(1-k)-f(1)}/[-k]
=-1/2 f'(1)
=-1/2×2
=-1