题目设f(x)可导,且满足 lim _(xarrow 0)dfrac (f(1)-f(1-2x))(x)=-2, 则曲线 =f(x) 在点(1,f(1))处的切线斜率为.-|||-()-|||-A. 4 B. -4 C. 1 D. -1题目解答答案