Hỏi đáp về Chương I Hàm số lượng giác và Phương trình lượng giác

A. \(y = {x^2} - {\mathop{\rm s}\nolimits} {\rm{in4}}x\)

B. \(y = \dfrac{{\sin x - \cot x}}{x}\)

C. \(y = {x^4} - \cos x\)

D. \(y = {x^2}\tan x\)

A. \(4\)                                  

B. \(6\)

C. \(5\)                                  

D. \(3\)

A. \(\,x = \dfrac{\pi }{8} + k\dfrac{\pi }{2};\,\,x = \dfrac{\pi }{4} + k\pi \)

B. \(x = k2\pi ;\,\,x = \dfrac{\pi }{2} + k2\pi \)

C. \(x = k\pi ;\,\,x = \dfrac{\pi }{4} + k\pi \)

D. \(x = k\pi ;\,\,x = k\dfrac{\pi }{2}\)

A. \(2\cos x - 1 = 0\)

B. \(2\cos x + 1 = 0\)

C. \(2\sin x + 1 = 0\)

D. \(2\sin x - \sqrt 3  = 0\)

A. \(m < 1 - \sqrt 3 \)

B. \(m > 1 + \sqrt 3 \)

C. \(1 - \sqrt 3  \le m \le 1 + \sqrt 3 \)

D. \( - \sqrt 3  \le m \le \sqrt 3 \)

A. \(\mathbb R\backslash \left\{ {k\pi ,k \in Z} \right\}\)

B. \(\mathbb R\)

C. \(\mathbb R\backslash \left\{ {{{k\pi } \over 2},k \in Z} \right\}\)

D. \([4;3]\)

A. \(x \ne \dfrac{\pi }{2} + k2\pi \)

B. \(x \ne k2\pi \)

C. \(x \ne \dfrac{{3\pi }}{2} + k2\pi \)

D. \(x \ne \pi  + k2\pi \)

A. \(y = 7 - 4\tan x\)           

B. \(y = \dfrac{7}{{{{\sin }^2}x}}\)

C. \(y = \dfrac{{\sin x + 1}}{{3 - \cos x}}\)                 

D. \(y = \cot x\)

A. \(m = \dfrac{{15}}{2}\)  

B. \(m = 5\)

C. \(m =  - \dfrac{5}{2}\)    

D. \(m =  - 5\)

A. \(\left[ \begin{array}{l}x = k\pi \\x = \dfrac{\pi }{4} + k\pi \end{array} \right.\)

B. \(\left[ \begin{array}{l}x = k\pi \\x = \dfrac{\pi }{2} + k\pi \end{array} \right.\)

C. \(\left[ \begin{array}{l}x = k\dfrac{\pi }{2}\\x = \dfrac{\pi }{2} + k\pi \end{array} \right.\)

D. \(\left[ \begin{array}{l}x = k\pi \\x = \dfrac{\pi }{4} + k\dfrac{\pi }{2}\end{array} \right.\)

A. \(\left[ \begin{array}{l}x =  - \dfrac{\pi }{{12}} + k\pi \\x = \dfrac{{5\pi }}{{12}} + k\pi \end{array} \right.\)

B. \(\left[ \begin{array}{l}x =  - \dfrac{\pi }{6} + k\pi \\x = \dfrac{\pi }{6} + k\dfrac{\pi }{2}\end{array} \right.\)

C. \(\left[ \begin{array}{l}x =  - \dfrac{\pi }{6} + k\pi \\x = \dfrac{\pi }{3} + k\pi \end{array} \right.\)

D. \(\left[ \begin{array}{l}x =  - \dfrac{\pi }{{12}} + k\pi \\x = \dfrac{{5\pi }}{{24}} + k\dfrac{\pi }{2}\end{array} \right.\)

A. \( - \sqrt 3  \le m \le \sqrt 3 \)

B. \(m \le  - \sqrt 3 ;\,\,m \ge \sqrt 3 \)

C. \( - \sqrt 5  \le m \le \sqrt 5 \)

D. \(m \le  - \sqrt 5 ;\,\,m \ge \sqrt 5 \)

A. \( - 1 \le m \le 1\)             

B. \(\dfrac{4}{3} \le m \le 2\)

C. \( - 2 \le m \le \dfrac{4}{3}\)         

D. \(\dfrac{4}{3} \le m \le 3\)

A. \(\left[ \begin{array}{l}x = \dfrac{\pi }{6} + k2\pi \\x = \dfrac{{7\pi }}{6} + k2\pi \end{array} \right.\)

B. \(\left[ \begin{array}{l}x =  - \dfrac{\pi }{6} + k2\pi \\x = \dfrac{{7\pi }}{6} + k2\pi \end{array} \right.\)

C. \(\left[ \begin{array}{l}x =  - \dfrac{\pi }{6} + k2\pi \\x = -\dfrac{{7\pi }}{6} + k2\pi \end{array} \right.\)

D. \(\left[ \begin{array}{l}x = \dfrac{\pi }{6} + k2\pi \\x = \dfrac{{5\pi }}{6} + k2\pi \end{array} \right.\)

A. \(x = \dfrac{\pi }{{20}} + k\dfrac{\pi }{5};\,x = \dfrac{\pi }{4} + k\pi \)

B. \(x = \dfrac{\pi }{{20}} + k\dfrac{\pi }{5};\,x = \dfrac{\pi }{4} + k\dfrac{\pi }{2}\)

C. \(x = \dfrac{\pi }{4} + k\pi ;\,x = \dfrac{\pi }{{20}} + k\dfrac{{2\pi }}{5}\)

D. \(x = k\pi ;\,x = \dfrac{\pi }{{10}} + k\dfrac{\pi }{5}\)

A. \(x = \dfrac{\pi }{2} + k2\pi \)

B. \(x = \pi  + k2\pi \)

C. \(x = \dfrac{\pi }{2} + k\pi \)

D. \(x = k2\pi \)

A. \(x = {40^0} + k{180^0}\)

B. \(x = {40^0} + k{90^0}\)

C. \(x = {40^0} + k{45^0}\)

D. \(x = {80^0} + k{180^0}\)

A. \(x =  - \dfrac{\pi }{3} + k2\pi ;\,\,\,x = \dfrac{{4\pi }}{3} + k2\pi \)

B. \(x = \dfrac{\pi }{6} + k2\pi ;\,\,\,x = \dfrac{{5\pi }}{6} + k2\pi \)

C. \(x =  - \dfrac{\pi }{6} + k2\pi ;\,\,\,x = \dfrac{{7\pi }}{6} + k2\pi \)

D. \(x = \dfrac{\pi }{3} + k2\pi ;\,\,\,x = \dfrac{{2\pi }}{3} + k2\pi \)

A. \(y = \sin x\)                    

B. \(y = \cos x\)

C. \(y = \cot x\)                    

D. \(y = \tan x\)

A. \(x = k2\pi ;\,\,x = \dfrac{{2\pi }}{3} + k2\pi \)

B. \(x =  - \dfrac{\pi }{3} + k2\pi ;\,\,x = \dfrac{{4\pi }}{3} + k2\pi \)

C. \(x =  - \dfrac{\pi }{6} + k2\pi ;\,\,x = \dfrac{\pi }{2} + k2\pi \)

D. \(x = \dfrac{\pi }{6} + k2\pi ;\,\,x = \dfrac{{5\pi }}{6} + k2\pi \)

A. \(9 - \cot x = 0\)

B. \(2\tan x + 9 = 0\)

C. \(1 - 4\sin x = 0\)

D. \(5 + 4\cos x = 0\)

A. \(M = 7\)                         

B. \(M = 5\)

C. \(M = 6\)                         

D. \(M = 8\)