8.已知函数f(x)=$\left\{\begin{array}{l}{{2}^{x-1}-1,x≥1}\\{-lo{g}_{2}(3-x),x<1}\end{array}\right.$,若f(a)=1,则f(1-a)=( )
| A. | 2 | B. | -2 | C. | 1 | D. | -1 |
7.已知O为原点,过双曲线$\frac{{x}^{2}}{{a}^{2}}$-y2=1(a>0)上点P作两条渐近线的平行线,且与两渐近线的交点分别为A,B,平行四边形OBPA的面积为1,则此双曲线的渐近线方程为( )
| A. | y=±$\frac{1}{2}$x | B. | y=±$\frac{\sqrt{2}}{2}$x | C. | y=±$\frac{1}{3}$x | D. | y=±$\frac{\sqrt{3}}{3}$x |
5.设集合U={1,2,3,4},集合A={x|2016x-2016=2016},集合C=(1,4],C∈N*;则∁UA∩C=( )
0 225268 225276 225282 225286 225292 225294 225298 225304 225306 225312 225318 225322 225324 225328 225334 225336 225342 225346 225348 225352 225354 225358 225360 225362 225363 225364 225366 225367 225368 225370 225372 225376 225378 225382 225384 225388 225394 225396 225402 225406 225408 225412 225418 225424 225426 225432 225436 225438 225444 225448 225454 225462 266669
| A. | {2,3} | B. | {4} | C. | {3,4} | D. | {1,2,3,4} |