lim 2/ n^2 +1 bằng

Đáp án đúng là: A

Có \(\mathop {\lim }\limits_{n \to + \infty } \frac{{\frac{2}{{{n^2}}}}}{{1 + \frac{1}{{{n^2}}}}} = 0\) vì \(\mathop {\lim }\limits_{n \to + \infty } \frac{2}{{{n^2}}} = 0;\,\,\mathop {\lim }\limits_{n \to + \infty } \frac{1}{{{n^2}}} = 0\).