Trắc nghiệm Toán 11 Bài 4 Cấp số nhân

A. \(q = 3\)

B. \(q = 2\)

C. \(q = 4\)    

D. \(q = \emptyset \)   

A. \(q = 3\)

B. \(q = 2\)

C. \(q = 4\)

D. \(q = \emptyset \)

A. \({u_1} = \frac{2}{9};{u_2} = \frac{2}{5};{u_3} = 2;{u_5} = 18;{u_6} = 54;{u_7} = 162\)

B. \({u_1} = \frac{2}{7};{u_2} = \frac{2}{3};{u_3} = 2;{u_5} = 18;{u_6} = 54;{u_7} = 162\)

C. \({u_1} = \frac{2}{9};{u_2} = \frac{2}{3};{u_3} = 2;{u_5} = 21;{u_6} = 54;{u_7} = 162\)

D. \({u_1} = \frac{2}{9};{u_2} = \frac{2}{3};{u_3} = 2;{u_5} = 18;{u_6} = 54;{u_7} = 162\)

A. \(x =  \pm 1\)

B. \(x =  \pm \sqrt 2 \)

C. \(x =  \pm 2\)

D. \(x =  \pm \sqrt 3 \)

A. \(\left[ \begin{array}{l}m =  - \frac{1}{{27}}\\m = 0\end{array} \right.\)

B. \(m \in \emptyset \)

C. \(\left[ \begin{array}{l}m =  - 1\\m = 0\end{array} \right.\)

D. \(\left[ \begin{array}{l}m =  - \frac{{10}}{{27}}\\m = 0\end{array} \right.\)

A. u_n = 5n+3, n ≥ 1

B.  u_n = 4+3n, n ≥ 1

C. \(\left\{ \begin{array}{l}
{u_1} = 3\\
{u_{n + 1}} = 7{u_n},n \ge 1
\end{array} \right.\)

D. \(\left\{ \begin{array}{l}
{u_1} = 2\\
{u_{n + 1}} = {u_n}^2,n \ge 1
\end{array} \right.\)

A. \(\frac{{512}}{{25}}\)

B. \(\frac{{125}}{{512}}\)

C. \(\frac{{625}}{{512}}\)

D. \(\frac{{512}}{{125}}\)

A. \(9 - 21\sqrt 2 \)

B. \(\frac{1}{2}\left( {18 - 21\sqrt 2 } \right)\)

C. \(\frac{1}{2}\left( {18 + 21\sqrt 2 } \right)\)

D. \(9 + 21\sqrt 2 \)

A. \(\sqrt {2\left( {\sqrt 2  + 1} \right)} \)

B. \(\frac{1}{2}\sqrt {\sqrt 2  + 1} \)

C. \(\frac{1}{2}\sqrt {2\left( {\sqrt 2  + 1} \right)} \)

D. \(\sqrt 2  + 1\)

A. (3, -1)

B. (-3, -1)

C. (-1,-3)     

D.  (-1,3)

A. 1,3,5,7,9     

B. -1,-3,1,3,5

C.  1,2,4,16,256 

D. 1,2,4,8,16

A. 2

B. 12

C. 24

D. 0

A. \(\frac{1}{3}\)

B. \(\sqrt 3 \)

C. 3

D. \(\frac{1}{{\sqrt 3 }}\)

A. x=14

B. x=32

C. x=64

D. x=68

A. \({30^ \circ };{60^ \circ };{90^ \circ }\)

B. \(\frac{\pi }{5};\frac{{2\pi }}{5};\frac{{4\pi }}{5}\)

C. \(\frac{\pi }{6};\frac{{2\pi }}{6};\frac{{4\pi }}{6}\)

D. \(\frac{\pi }{7};\frac{{2\pi }}{7};\frac{{4\pi }}{7}\)

A. 2

B. 0

C. \(\frac{4}{3}\)

D. \(\frac{2}{3}\)