Lim {2^{2n / 2^{n + 1 . 4n - 3/ 2n + 1 bằng

13/39

\(\lim \left( {\frac{{{2^{2n}}}}{{{2^{n + 1}}}} \cdot \frac{{4n - 3}}{{2n + 1}}} \right)\) bằng

\[ + \infty \].

\[ - \infty \].

\[6\].

\[2\].

Giải thích

Chọn A

Ta có \(\lim \left( {\frac{{{2^{2n}}}}{{{2^{n + 1}}}} \cdot \frac{{4n - 3}}{{2n + 1}}} \right) = \lim \left( {{2^n}.\frac{1}{2} \cdot \frac{{4n - 3}}{{2n + 1}}} \right) = + \infty \), vì \(\lim {2^n} = + \infty ,\lim \left( {\frac{1}{2} \cdot \frac{{4n - 3}}{{2n + 1}}} \right) = 1\).