\(\lim \;\frac{{10}}{{\sqrt {{n^4} + {n^2} + 1} }}...

C

- Hướng dẫn giải

\(\lim \;\frac{{10}}{{\sqrt {{n^4} + {n^2} + 1} }} = \lim \frac{{10}}{{{n^2}\sqrt {1 + \frac{1}{{{n^2}}} + \frac{1}{{{n^4}}}} }} = 0\)

vì \(\lim \sqrt {1 + \frac{1}{{{n^2}}} + \frac{1}{{{n^4}}}}  = 1,\lim \frac{{10}}{{{n^2}}} = 0\)