13.若x,y满足$\left\{\begin{array}{l}y≥0\\ x-y+3≥0\\ kx-y+3≥0\end{array}\right.$且z=2x+y的最大值为4,则k的值为( )
| A. | $-\frac{3}{2}$ | B. | $\frac{3}{2}$ | C. | $-\frac{2}{3}$ | D. | $\frac{2}{3}$ |
12.已知函数f (x) 的部分对应值如表所示.数列{an}满足a1=1,且对任意n∈N*,点(an,an+1)都在函数f(x)的图象上,则a2016的值为( )
| x | 1 | 2 | 3 | 4 |
| f(x) | 3 | 1 | 2 | 4 |
| A. | 1 | B. | 2 | C. | 3 | D. | 4 |
11.已知两点O(0,0),A(-2,0),以线段OA为直径的圆的方程是( )
| A. | (x-1)2+y2=4 | B. | (x+1)2+y2=4 | C. | (x-1)2+y2=1 | D. | (x+1)2+y2=1 |
10.下列函数中,在区间(0,+∞)上为增函数的是( )
| A. | $y=\sqrt{x}$ | B. | $y=\frac{1}{x}$ | C. | $y={(\frac{1}{2})^x}$ | D. | $y={log_{\frac{1}{2}}}x$ |
9.若集合 A={-2,-1,0,1,2},B={x|x2>1},则 A∩B=( )
0 225348 225356 225362 225366 225372 225374 225378 225384 225386 225392 225398 225402 225404 225408 225414 225416 225422 225426 225428 225432 225434 225438 225440 225442 225443 225444 225446 225447 225448 225450 225452 225456 225458 225462 225464 225468 225474 225476 225482 225486 225488 225492 225498 225504 225506 225512 225516 225518 225524 225528 225534 225542 266669
| A. | {x|x<-1或x>1} | B. | {-2,2} | C. | {2} | D. | {0} |