8.设集中A={2,4,6},B={1,9,25,49,81,100},下面的对应关系f能构成A到B的映射的是( )
| A. | f:x→(2x-1)2 | B. | f:x→(2x-3) | C. | f:x→(2x-1) | D. | f:x→(2x-3)2 |
7.下列集合中表示同一集合的是( )
| A. | M={整数},N={整数集} | B. | M={(3,2)},N={(2,3)} | ||
| C. | M={(x,y)|x+y=1},N={(y,x)|x+y=1} | D. | M={1,2},N={(1,2)} |
6.已知{1,2}⊆M?{1,2,3,4},则这样的集合M有( )个.
| A. | 2 | B. | 3 | C. | 4 | D. | 5 |
5.函数y=|x-1|与y=lgx图象交点个数为( )
| A. | 3 | B. | 2 | C. | 1 | D. | 0 |
1.设角α的终边经过点P(-3a,4a),(a>0),则sinα+2cosα等于( )
0 224371 224379 224385 224389 224395 224397 224401 224407 224409 224415 224421 224425 224427 224431 224437 224439 224445 224449 224451 224455 224457 224461 224463 224465 224466 224467 224469 224470 224471 224473 224475 224479 224481 224485 224487 224491 224497 224499 224505 224509 224511 224515 224521 224527 224529 224535 224539 224541 224547 224551 224557 224565 266669
| A. | $\frac{1}{5}$ | B. | -$\frac{1}{5}$ | C. | -$\frac{2}{5}$ | D. | $\frac{2}{5}$ |