- Phương trình lượng giác đẳng cấp cos, sin - có l...

A \(\left[ \matrix{x = {\pi \over 2} + k\pi \hfill \cr x = {\pi \over 6} + k\pi \hfill \cr} \right.\,\,\left( {k \in Z} \right)\)

B \(\left[ \matrix{x = {\pi \over 4} + k\pi \hfill \cr x = {\pi \over 3} + k\pi \hfill \cr} \right.\,\,\left( {k \in Z} \right)\)

C \(\left[ \matrix{x = {\pi \over 8} + k\pi \hfill \cr x = {\pi \over {12}} + k\pi \hfill \cr} \right.\,\,\left( {k \in Z} \right)\)

D \(\left[ \matrix{x = {{3\pi } \over 4} + k\pi \hfill \cr x = {{2\pi } \over 3} + k\pi \hfill \cr} \right.\,\,\left( {k \in Z} \right)\)

A \(\left[ \matrix{x = - {\pi \over 4} + k\pi \hfill \cr x = \alpha + k\pi \hfill \cr} \right.\,\,\left( {với \,\tan \alpha = - 2 + \sqrt 3 } \right)\,\,\left( {k \in Z} \right)\)

B \(\left[ \matrix{x = {\pi \over 4} + k\pi \hfill \cr x = \alpha + k\pi \hfill \cr} \right.\,\,\left( {với \,\tan \alpha = 2 - \sqrt 3 } \right)\,\,\left( {k \in Z} \right)\)

C \(\left[ \matrix{x = - {\pi \over 8} + k\pi \hfill \cr x = \alpha + k\pi \hfill \cr} \right.\,\,\left( {với \,\tan \alpha = - 1 + \sqrt 3 } \right)\,\,\left( {k \in Z} \right)\)

D \(\left[ \matrix{x = {\pi \over 8} + k\pi \hfill \cr x = \alpha + k\pi \hfill \cr} \right.\,\,\left( {với \,\tan \alpha = 1 - \sqrt 3 } \right)\,\,\left( {k \in Z} \right)\)

A \(x = {1 \over 2}\arctan 3 + {{k\pi } \over 2}\,\,,\,\,x = {1 \over 2}\arctan \left( { - 2} \right) + {{k\pi } \over 2}\,\,\left( {k \in Z} \right)\)

B \(x = \arctan {{1 + \sqrt {73} } \over {12}} + {{k\pi } \over 2}\,\,,\,\,x = \arctan {{1 - \sqrt {73} } \over {12}} + {{k\pi } \over 2}\,\,\left( {k \in Z} \right)\)

C \(x = {1 \over 2}\arctan {{1 + \sqrt {73} } \over 6} + {{k\pi } \over 2}\,\,,\,\,x = {1 \over 2}\arctan {{1 - \sqrt {73} } \over 6} + {{k\pi } \over 2}\,\,\left( {k \in Z} \right)\)

D \(x = \arctan {3 \over 2} + {{k\pi } \over 2}\,\,,\,\,x = \arctan \left( { - 1} \right) + {{k\pi } \over 2}\,\,\left( {k \in Z} \right)\)

A \({\pi  \over 6} + k\pi \,\,\left( {k \in Z} \right)\)

B \({\pi  \over 4} + k\pi \,\,\left( {k \in Z} \right)\)

C \( - {\pi  \over 4} + k\pi \,\,\left( {k \in Z} \right)\)

D \( - {\pi  \over 4} + k2\pi \,\,\left( {k \in Z} \right)\)

A \(x =  - {\pi  \over 5} + k\pi \,\,\left( {k \in Z} \right)\)

B \(x =  - {\pi  \over {12}} + {{k\pi } \over 2}\,\,\left( {k \in Z} \right)\)

C \(x =  - {\pi  \over {18}} + {{k\pi } \over 3}\,\,\left( {k \in Z} \right)\)

D \(x =  - {\pi  \over {24}} + {{k\pi } \over 4}\,\,\left( {k \in Z} \right)\)

A Ba nghiệm       

B Một nghiệm

C Hai nghiệm 

D Bốn nghiệm

A \(x =  \pm {\pi  \over 4} + k2\pi \,\,\left( {k \in Z} \right)\)

B \(x = {\pi  \over 4} + {{k\pi } \over 2}\,\,\left( {k \in Z} \right)\)

C \(x =  \pm {\pi  \over 4} + {{k\pi } \over 3}\,\,\left( {k \in Z} \right)\)

D \(x = {\pi  \over 4} + k\pi \,\,\left( {k \in Z} \right)\)

A \(x = {\pi  \over 4} + k2\pi \,,\,x = \arctan \left( { - 1 \pm \sqrt 2 } \right) + k2\pi \)

B \(x = {\pi  \over 2} + {{k\pi } \over 2},x = \arctan \left( { - 1 \pm \sqrt 2 } \right) + {{k\pi } \over 2}\)

C \(x = {\pi  \over 4} + {{k2\pi } \over 3}\,,\,x = \arctan \left( { - 1 \pm \sqrt 2 } \right) + {{k2\pi } \over 3}\)

D \(x = {\pi  \over 4} + k\pi \,,\,x = \arctan \left( { - 1 \pm \sqrt 2 } \right) + k\pi \)

A \(\left[ \matrix{x = - {\pi \over 4} + k2\pi \hfill \cr x = \pm {\pi \over 3} + k2\pi \hfill \cr} \right.\,\,\left( {k \in Z} \right)\)

B \(\left[ \matrix{x = - {\pi \over 4} + {{k\pi } \over 2} \hfill \cr x = \pm {\pi \over 3} + {{k\pi } \over 2} \hfill \cr} \right.\,\,\left( {k \in Z} \right)\)

C \(\left[ \matrix{x = - {\pi \over 4} + {{k2\pi } \over 3} \hfill \cr x = \pm {\pi \over 3} + {{k2\pi } \over 3} \hfill \cr} \right.\,\,\left( {k \in Z} \right)\)

D \(\left[ \matrix{x = - {\pi \over 4} + k\pi \hfill \cr x = \pm {\pi \over 3} + k\pi \hfill \cr} \right.\,\,\left( {k \in Z} \right)\)

A \(x = {\pi  \over 4} + k2\pi \,\,,\,\,x =  \pm {\pi  \over 3} + k2\pi \,\,\left( {k \in Z} \right)\)

B \(x = {\pi  \over 4} + {{k\pi } \over 2}\,\,,\,\,x =  \pm {\pi  \over 3} + {{k\pi } \over 2}\,\,\left( {k \in Z} \right)\)

C \(x = {\pi  \over 4} + {{k\pi } \over 3}\,\,,\,\,x =  \pm {\pi  \over 3} + {{k\pi } \over 3}\,\,\left( {k \in Z} \right)\)

D \(x = {\pi  \over 4} + k\pi \,\,,\,\,x =  \pm {\pi  \over 3} + k\pi \,\,\left( {k \in Z} \right)\)

A \(\left[ \matrix{x = \arctan \left( { - 2} \right) + k2\pi \hfill \cr x = {\pi \over 4} + k2\pi \hfill \cr} \right.\,\,\left( {k \in Z} \right)\)

B \(\left[ \matrix{x = \arctan \left( { - 2} \right) + {{k\pi } \over 2} \hfill \cr x = {\pi \over 4} + {{k\pi } \over 2} \hfill \cr} \right.\,\,\left( {k \in Z} \right)\)

C \(\left[ \matrix{x = \arctan \left( { - 2} \right) + {{k2\pi } \over 3} \hfill \cr x = {\pi \over 4} + {{k2\pi } \over 3} \hfill \cr} \right.\,\,\left( {k \in Z} \right)\)

D \(\left[ \matrix{x = \arctan \left( { - 2} \right) + k\pi \hfill \cr x = {\pi \over 4} + k\pi \hfill \cr} \right.\,\,\left( {k \in Z} \right)\)

A \(x = {\pi  \over 4} + {{k\pi } \over 2}\,\,\left( {k \in Z} \right)\)

B \(x = {\pi  \over 4} + k\pi \,\,\left( {k \in Z} \right)\)

C \(x =  - {\pi  \over 4} + {{k\pi } \over 2}\,\,\left( {k \in Z} \right)\)

D \(x =  - {\pi  \over 4} + k\pi \,\,\left( {k \in Z} \right)\)

A \(\left[ \matrix{x = {\pi \over 6} + {{k2\pi } \over 3} \hfill \cr x = {{k2\pi } \over 3} \hfill \cr} \right.\,\,\left( {k \in Z} \right)\)

B \(\left[ \matrix{x = - {\pi \over 6} + {{k2\pi } \over 3} \hfill \cr x = {{k2\pi } \over 3} \hfill \cr} \right.\,\,\left( {k \in Z} \right)\)

C \(\left[ \matrix{x = \pm {\pi \over 6} + {{k2\pi } \over 3} \hfill \cr x = {{k2\pi } \over 3} \hfill \cr} \right.\,\,\left( {k \in Z} \right)\)

D \(x = {{k2\pi } \over 3}\,\,\left( {k \in Z} \right)\)

A \(x = {\pi  \over 2} + k\pi \,\,\left( {k \in Z} \right)\)

B \(\left[ \matrix{x = {\pi \over 4} + k\pi \hfill \cr x = \arctan \left( { - 2} \right) + k\pi \hfill \cr} \right.\,\,\left( {k \in Z} \right)\)

C \(x =  - {\pi  \over 4} + k\pi \,\,\left( {k \in Z} \right)\)

D Vô nghiệm

A 0

B 1

C 2

D 3

A 0

B 1

C 2

D 3

A 0

B 1

C 2

D 3

A \(x = {\pi  \over 2} + k\pi \,\,\left( {k \in Z} \right)\)

B \(\left[ \matrix{x = {\pi \over 2} + k\pi \hfill \cr x = k\pi \hfill \cr} \right.\,\,\left( {k \in Z} \right)\)

C \(x = k\pi \,\,\left( {k \in Z} \right)\)

D Vô nghiệm

A 0

B 1

C 2

D 3

A 4

B 3

C 2

D 1