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

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

B. \(x = k\pi \)

C. Phương trình vô nghiệm

D. \(x = \dfrac{\pi }{4} + k\pi \)

A. \(x = \dfrac{\pi }{6} + k\dfrac{\pi }{2};\,\,x = k\dfrac{\pi }{4}\)

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

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

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

A. \(m \le 1\)                            

B. \(0 \le m \le 1\)

C. \( - 1 \le m \le 1\)                  

D. \(m \ge 0\)

A. \(\dfrac{{2\pi }}{3}\)                      

B. \(\dfrac{\pi }{3}\)

C. \(\dfrac{{4\pi }}{3}\)                      

D. \(\dfrac{{7\pi }}{3}\)

A. \(1\)                                     

B. \(2\)

C. \(6\)                                     

D. \(4\)

A. \(\sin x =  - 1 \Leftrightarrow x = \dfrac{{ - \pi }}{2} + k2\pi \)

B. \(\sin x = 0 \Leftrightarrow x = k\pi \)

C. \(\sin x = 0 \Leftrightarrow x = k2\pi \)

D. \(\sin x = 1 \Leftrightarrow x = \dfrac{\pi }{2} + k2\pi \)

A. \(\sqrt 2 ;\,2\)              

B. \(2;\,4\)                       

C. \(4\sqrt 2 ;\,\,8\)          

D. \(4\sqrt 2  - 1;\,\,7\) 

A. Hàm số \(y = \sin x\) tăng trong khoảng \(\left( {0;\dfrac{\pi }{2}} \right)\)

B. Hàm số \(y = \cot x\) giảm trong khoảng \(\left( {0;\dfrac{\pi }{2}} \right)\)

C. Hàm số \(y = \tan x\) tăng trong khoảng \(\left( {0;\dfrac{\pi }{2}} \right)\)

D. Hàm số \(y = \cos x\) tăng trong khoảng \(\left( {0;\dfrac{\pi }{2}} \right)\)

A. \(x =  - \dfrac{\pi }{{12}} - k2\pi ;\,\,x = \dfrac{{19\pi }}{{12}} - k2\pi \)

B. \(x = \dfrac{{7\pi }}{{12}} + k2\pi ;\,\,x =  - \dfrac{{13\pi }}{{12}} + k2\pi \)

C. \(x = \dfrac{\pi }{{12}} + k2\pi ;\,\,x = \dfrac{{19\pi }}{{12}} + k2\pi \)

D. \(x =  - \dfrac{{7\pi }}{{12}} - k2\pi ;\,\,x = \dfrac{{13\pi }}{{12}} - k2\pi \)

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

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

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

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

A. \(x = \dfrac{\pi }{{12}} + k\dfrac{\pi }{4}\)

B. \(x = \dfrac{\pi }{8} + k\dfrac{\pi }{4}\)

C. \(x = k\dfrac{\pi }{4}\)

D. \(x = \dfrac{\pi }{{24}} + k\dfrac{\pi }{4}\)

A. \(\left[ \begin{array}{l}x = \dfrac{\pi }{4} + k\dfrac{{2\pi }}{3}\\x = \dfrac{{3\pi }}{4} + k2\pi \end{array} \right.\)

B. \(\left[ \begin{array}{l}x =  - \dfrac{\pi }{4} + k2\pi \\x =  - \dfrac{\pi }{{12}} + k\dfrac{{2\pi }}{3}\end{array} \right.\)

C. \(\left[ \begin{array}{l}x = \dfrac{\pi }{4} + k2\pi \\x = \dfrac{{4\pi }}{9} + k\dfrac{{2\pi }}{3}\end{array} \right.\)

D. \(\left[ \begin{array}{l}x = \dfrac{\pi }{4} + k2\pi \\x = \dfrac{\pi }{{12}} + k\dfrac{{2\pi }}{3}\end{array} \right.\)

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

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

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

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