Question

求极限 u→1时 lim（u^n-1)/(u-1)

Answer 1

lim（u^n-1)/(u-1)u→1时

分子分母同时趋向于0 适用罗比塔法则

=lim（u^n-1)'/(u-1)'

=lim[nu^(n-1)]u→1时

=n