Câu 36:
Tìm L=lim(11+11+2+ ... +11+2+ ... +n).L=\lim \left( \dfrac{1}{1}+\dfrac{1}{1+2}+\,...\,+\dfrac{1}{1+2+\,...\,+n} \right).L=lim(11+1+21+...+1+2+...+n1).
