17.设全集I={0,1,2,3,4},集合A={0,1,2,3},集合B={2,3,4},则∁IA∪∁IB=( )
| A. | {0} | B. | {0,1} | C. | {0,1,4} | D. | {0,1,2,3,4} |
9.函数y=f(x)是R上的偶函数,且在(-∞,0]上是增函数,若$f(a)≥f(\frac{1}{3})$,则a的取值范围是( )
| A. | $a≥\frac{1}{3}$ | B. | $a≤-\frac{1}{3}$ | C. | $-\frac{1}{3}≤a≤\frac{1}{3}$ | D. | $a≥\frac{1}{3}$或$a≤-\frac{1}{3}$ |
8.下列函数在(0,+∞)上是增函数并且是定义域上的偶函数的是( )
0 234315 234323 234329 234333 234339 234341 234345 234351 234353 234359 234365 234369 234371 234375 234381 234383 234389 234393 234395 234399 234401 234405 234407 234409 234410 234411 234413 234414 234415 234417 234419 234423 234425 234429 234431 234435 234441 234443 234449 234453 234455 234459 234465 234471 234473 234479 234483 234485 234491 234495 234501 234509 266669
| A. | $y={x^{\frac{2}{3}}}$ | B. | $y={(\frac{1}{2})^x}$ | C. | y=lnx | D. | y=x2+2x+1 |