17.已知函数$f(x)=\left\{\begin{array}{l}x(x+4),x≥0\\ x(x-4),x<0\end{array}\right.$,则f[f(-1)]的值是( )
| A. | 40 | B. | 42 | C. | 44 | D. | 45 |
16.经过点A(3,2),且与直线x-y+3=0平行的直线方程是( )
| A. | x+y-1=0 | B. | x-y-1=0 | C. | x+y+1=0 | D. | x-y+1=0 |
15.函数f(x)=$\sqrt{1-x}$+lg(3x+1)的定义域是( )
| A. | (-∞,$-\frac{1}{3}$) | B. | (-$\frac{1}{3}$,$\frac{1}{3}$) | C. | ($-\frac{1}{3}$,1] | D. | ($-\frac{1}{3}$,+∞) |
14.集合U={1,2,3,4,5,6},A={1,3,5},B={2,4,5},则A∩∁UB=( )
0 235448 235456 235462 235466 235472 235474 235478 235484 235486 235492 235498 235502 235504 235508 235514 235516 235522 235526 235528 235532 235534 235538 235540 235542 235543 235544 235546 235547 235548 235550 235552 235556 235558 235562 235564 235568 235574 235576 235582 235586 235588 235592 235598 235604 235606 235612 235616 235618 235624 235628 235634 235642 266669
| A. | {1} | B. | {1,3} | C. | {1,3,6} | D. | {2,4,5} |