Giải thích các bước giải:
\(\begin{array}{l}
1d.\lim \frac{{1 - {{\left( {\frac{3}{4}} \right)}^n}}}{{3 + {{\left( {\frac{2}{4}} \right)}^n}}} = \frac{1}{3}\\
2b.\lim {n^4}.\left( { - 2 + \frac{1}{n} - \frac{2}{{{n^3}}} + \frac{5}{{{n^4}}}} \right) = - \infty \\
Do:\mathop {\lim }\limits_{x \to \infty } {n^4} = + \infty \\
\lim \left( { - 2 + \frac{1}{n} - \frac{2}{{{n^3}}} + \frac{5}{{{n^4}}}} \right) = - 2
\end{array}\)
