3.执行如图所示的程序框图,如果输入的m,n分别为1848,936,则输出的m等于( )

| A. | 168 | B. | 72 | C. | 36 | D. | 24 |
1.在△ABC中,a,b,c分别为角A,B,C的对边,且满足4cos2$\frac{A}{2}$-cos2(B+C)=$\frac{7}{2}$,若a=2,则△ABC的面积的最大值是( )
| A. | 1 | B. | $\sqrt{3}$ | C. | 2 | D. | $2\sqrt{3}$ |
20.已知平面向量$\overrightarrow{OA}$、$\overrightarrow{OB}$、$\overrightarrow{OC}$满足:|$\overrightarrow{OA}$|=|$\overrightarrow{OB}$|=|$\overrightarrow{OC}$|=1,$\overrightarrow{OA}$•$\overrightarrow{OB}$=0.若$\overrightarrow{OC}$=x$\overrightarrow{OA}$+y$\overrightarrow{OB}$,(x,y∈R),则x+y的最大值是( )
| A. | $\frac{{\sqrt{2}}}{2}$ | B. | 1 | C. | $\sqrt{2}$ | D. | 2 |
19.已知$cos(θ-\frac{π}{2})=\frac{4}{5}$,且sinθ-cosθ>1,则sin(2θ-2π)=( )
0 232227 232235 232241 232245 232251 232253 232257 232263 232265 232271 232277 232281 232283 232287 232293 232295 232301 232305 232307 232311 232313 232317 232319 232321 232322 232323 232325 232326 232327 232329 232331 232335 232337 232341 232343 232347 232353 232355 232361 232365 232367 232371 232377 232383 232385 232391 232395 232397 232403 232407 232413 232421 266669
| A. | $-\frac{24}{25}$ | B. | $-\frac{12}{25}$ | C. | $-\frac{4}{5}$ | D. | $\frac{24}{25}$ |