Tính giới hạn lim ((n^2-n+3)/(2n^2+n+1))

* Hướng dẫn giải

Đáp án D

Ta có:

$$\begin{gathered} \lim \frac{n^2-n+3}{2n^2+n+1}=\lim \frac{n^2\left(1-\frac{1}{n}+\frac{3}{n^2}\right)}{n^2\left(2+\frac{1}{n}+\frac{1}{n^2}\right)} \\ =\lim \frac{1-\frac{1}{n}+\frac{3}{n^2}}{2+\frac{1}{n}+\frac{1}{n^2}}=\frac{1}{2} \end{gathered}$$