Câu hỏi:

$D = \mathbb{R}\backslash \left\{ {\frac{\pi }{2} + k\pi ,k \in \mathbb{Z}} \right\}.$

C. $\left[ \begin{gathered}

x = \frac{\pi }{6} + k\pi \hfill \\

x = \frac{{5\pi }}{6} + k\pi \hfill \\

D. $\left[ \begin{gathered}

x = \frac{\pi }{3} + k2\pi \hfill \\

x = \frac{{2\pi }}{3} + k2\pi \hfill \\

\end{gathered} \right.,k \in \mathbb{Z}$

$9;\,7 & ;\,5;\,3;\,1;\,0$

\[0;\,1;\,2;\, - 3;\,7\].2

A. \[\left( {{u_n}} \right):\left\{ \begin{gathered}

{u_1} = 1 \hfill \\

{u_{n + 1}} = {u_n} + 2,\forall n \geqslant 1 \hfill \\

B. \[\left( {{u_n}} \right):\left\{ \begin{gathered}

{u_1} = 3 \hfill \\

{u_{n + 1}} = 2{u_n} + 1,\forall n \geqslant 1 \hfill \\

D. \[\left( {{u_n}} \right): - 1;1; - 1;1; - 1;...\]

D. \[{S_{16}} = 24\]

D. \[ - 2;10;50;250\]

B. \[\lim {q^n} = 0\left( {\left| q \right| > 1} \right)\].

D. \[\lim \frac{1}{{{n^k}}} = 0\left( {k > 1} \right)\]

D. \[L = 2\]

D. \[\mathop {\lim }\limits_{x \to - \infty } f\left( x \right) = + \infty \]