lim(x^n-1)/(x-1)(x趨向於1n為正整數)的極限

lim(x^n-1)/(x-1)(x趨向於1n為正整數)的極限

lim(x^n-1)/(x-1)=limx^(n-1)+x^(n-2)+…+1
故x趨向於1時,其極限為n