Question

Chứng minh các giới hạn sau :

\(1.lim\dfrac{n^2+1}{n}=+\infty\)

\(2.lim\dfrac{2-n}{\sqrt{n}}=-\infty\)

Answer 1

1. \(lim_{n\rightarrow+\infty}\dfrac{n^2+1}{n}=lim_{n\rightarrow+\infty}\left(n+\dfrac{1}{n}\right)=+\infty\)(đpcm)

2. \(lim_{n\rightarrow+\infty}\dfrac{2-n}{\sqrt{n}}=lim_{n\rightarrow+\infty}\left(2-\sqrt{n}\right)=-\infty\) (đpcm)