一、求极限公式(2) (3) (4)(5)(6) (7) (8)二、方法(1)分母极限为0时,分解因式,凑公式(2)当时,除以最高指数的Xn(3)等价无穷小量代换sinxx;tanx;arctanxx;arcsinxx; 导数: (1)(C)=0 (2)(x)=x1(3)(4)(5)(ax)=axlna(a0,a1) (6)(ex)=ex (7)(8)(9)(sinx)=cosx (10)(cosx)= sinx (11)(12)(13)(secx)=secxtanx (14)(cscx)= cscxcotx(15)(16)(17)(18)三。导数的四则运算法则设u=u(x),v=v(x)均为x的可导函数,则有(1)(uv)=uv(2)(uv)=uv+uv(3)(cu)=cu(4)(5)(6)(uvw)=uvw+uvw+uvw