Question

求函数y=x³-2x+1在x=2处的导数.

Answer 1

你需要的应该是用定义求导吧?给出如下：

f'(2) = lim(h→0)[f(2+h)-f(2)]/h

= lim(h→0){[(2+h)³-2(2+h)+1] - (2³-2*2+1)}/h

= lim(h→0)[(2+h)^2 + (2+h)2 + 2^2 - 2]

= 10.