Tìm số nghiệm có dạng \[\frac{{{\rm{m\pi }}}}{{\rm{3}}}{\rm{,}}\,{\rm{m}} \in \mathbb{Z}\] trên đoạn\[\left[ {{\rm{0; 2\pi }}} \right]\] của phương trình\[{\rm{1 + sinx + cosx + sin2x + cos2x = 0}}\]

A. \[\left\{ {\frac{{\rm{\pi }}}{{\rm{4}}}{\rm{ + }}\frac{{{\rm{k\pi }}}}{{\rm{2}}}} \right\}\]

B. \[\left\{ {\frac{{{\rm{k\pi }}}}{{\rm{4}}}} \right\}\]

C. \[\left\{ {{\rm{k\pi ; }}\frac{{\rm{\pi }}}{{\rm{4}}}{\rm{ + }}\frac{{{\rm{k\pi }}}}{{\rm{2}}}} \right\}\]

D. \[\left\{ {{\rm{k\pi ; }}\frac{{\rm{\pi }}}{{\rm{4}}}{\rm{ + k\pi }}} \right\}\]

A. 29

B. 41

C. 34

D. 13

A. 2

B. 3

C. 5

D. 4

A. \(\left[ {\begin{array}{*{20}{c}}{{\rm{x = }}\frac{{\rm{\pi }}}{{{\rm{12}}}}{\rm{ + k2\pi }}}\\{{\rm{x = }}\frac{{{\rm{11\pi }}}}{{{\rm{12}}}}{\rm{ + }}l{\rm{2\pi }}}\end{array}} \right.\left( {k,l \in \mathbb{Z}} \right)\)

B. \(\left[ {\begin{array}{*{20}{c}}{{\rm{x = }}\frac{{\rm{\pi }}}{{{\rm{12}}}}{\rm{ + k2\pi }}}\\{{\rm{x = }} - \frac{{\rm{\pi }}}{{{\rm{12}}}}{\rm{ + k2\pi }}}\end{array}} \right.\left( {k \in \mathbb{Z}} \right)\)

C. \({\rm{x = }}\frac{{\rm{\pi }}}{{{\rm{12}}}}{\rm{ + k2\pi }}\left( {k \in \mathbb{Z}} \right)\)

D. \({\rm{x = }}\frac{{{\rm{11\pi }}}}{{{\rm{12}}}}{\rm{ + k2\pi }}\,\left( {k \in \mathbb{Z}} \right)\)

A. \[{\rm{x = \pm }}\frac{{{\rm{2\pi }}}}{{\rm{3}}}{\rm{ + k2\pi }}\]

B. \[{\rm{x = \pm }}\frac{{\rm{\pi }}}{{\rm{6}}}{\rm{ + k\pi }}\]

C. \[{\rm{x = \pm }}\frac{{\rm{\pi }}}{{\rm{3}}}{\rm{ + k2\pi }}\]

D. \[{\rm{x = \pm }}\frac{{\rm{\pi }}}{{\rm{6}}}{\rm{ + k2\pi }}\]

A. 32^∘C, lúc 15 giờ.

B. 29^∘C, lúc 9 giờ.

C. 26^∘C, lúc 3 giờ.

D. 26^∘C, lúc 0 giờ.

A. \(\left[ {\begin{array}{*{20}{c}}{{\rm{x = }}\frac{{\rm{\pi }}}{{\rm{3}}}{\rm{ + k2\pi }}}\\{{\rm{x = }} - \frac{{\rm{\pi }}}{{\rm{3}}}{\rm{ + k2\pi }}}\end{array}} \right.\left( {k \in \mathbb{Z}} \right)\)

B. \(\left[ {\begin{array}{*{20}{c}}{{\rm{x = }}\frac{{\rm{\pi }}}{{\rm{3}}}{\rm{ + k2\pi }}}\\{{\rm{x = }}\frac{{{\rm{2\pi }}}}{{\rm{3}}}{\rm{ + k2\pi }}}\end{array}} \right.\left( {k \in \mathbb{Z}} \right)\)

C. \({\rm{x = }}\frac{{\rm{\pi }}}{{\rm{3}}}{\rm{ + k\pi }}\)\(\left( {k \in \mathbb{Z}} \right)\)

D. \(\left[ {\begin{array}{*{20}{c}}{{\rm{x = }}\frac{{\rm{\pi }}}{{\rm{3}}}{\rm{ + k\pi }}}\\{{\rm{x = }}\frac{{{\rm{2\pi }}}}{{\rm{3}}}{\rm{ + k\pi }}}\end{array}} \right.\left( {k \in \mathbb{Z}} \right)\)