Question

X趋近于a X的m次幂减去a的m次幂分子X的n次幂减去a的n次幂大神们帮帮忙

Answer 1

(x^m-a^m)/(x^n-a^n) =(x-a)(x^(m-1)+ax^(m-2)+……+a^(m-1))/(x-a)(x^(n-1)+ax^(n-2)+……+a^(n-1)) =(x^(m-1)+ax^(m-2)+……+a^(m-1))/(x^(n-1)+ax^(n-2)+……+a^(n-1)) x趋近a =ma^(m-1)/na^(n-1) =m/n*a^(m-n)