1【罗必塔法则】lim(x->1) tan(x-1)/(x^2-1) =lim(x->1) [ 1/cox(x-1)^2 ]/2x= 1/22【等价无穷小量代换】x->1 时,t = x-1 -> 0t->0 时,tant t --> tan(x-1) (x-1)lim(x->1) tan(x-1)/(x^2-1)=lim(x->1) (x-1)/(x^2-1...