Question

请教两道离散数学题

1.Show that (x^2+xy +x log y)^3 is in O(x^6 y^3).
2.Show that (n+2)/n is in o(n).

Answer 1

1.即证lim(x->0,y->0)(x^2+xy +x log y)^3/(x^6 y^3)=const
按照求二重极限的方法做
2.即证lim(n->∞)(n+2)/n^2=0
这个很显然