15.已知集合U={0,1,2,3,4},M={1,3},N={1,2,4},则为(∁uM)∩N( )
| A. | {1,3,4} | B. | {0,2,4} | C. | {2,4} | D. | {3,4} |
14.在△ABC中,角A,B,C的对边分别为a,b,c,若$sinA=2sinB,cosC=-\frac{1}{4}$,则$\frac{c}{a}$=( )
| A. | $\sqrt{6}$ | B. | $\frac{{\sqrt{6}}}{2}$ | C. | $\sqrt{3}$ | D. | $\frac{{\sqrt{3}}}{2}$ |
13.“a>4”是“方程x2+ax+a=0有两个负实数根”的( )
| A. | 充分不必要条件 | B. | 必要不充分条件 | ||
| C. | 充要条件 | D. | 既不充分也不必要条件 |
12.已知$z=\frac{2-i}{1+i}-{i^{2016}}$(i是虚数单位),则|z|=( )
| A. | 2 | B. | 4 | C. | $\frac{{\sqrt{10}}}{2}$ | D. | $\frac{5}{2}$ |
11.已知集合U={x∈Z|x2-x-12≤0},A={-2,-1,3},B={0,1,3,4},则(∁∪A)∩B=( )
| A. | {0,2,4} | B. | {0,1,4} | C. | {0,4} | D. | {1,3} |
6.设等差数列{an}的前n项和为Sn,若数列{an}是单调递增数列,且满足a5≤6,S3≥9,则a6的取值范围是( )
0 227253 227261 227267 227271 227277 227279 227283 227289 227291 227297 227303 227307 227309 227313 227319 227321 227327 227331 227333 227337 227339 227343 227345 227347 227348 227349 227351 227352 227353 227355 227357 227361 227363 227367 227369 227373 227379 227381 227387 227391 227393 227397 227403 227409 227411 227417 227421 227423 227429 227433 227439 227447 266669
| A. | (3,6] | B. | (3,6) | C. | [3,7] | D. | (3,7] |