16.若定义运算a*b为:a*b=$\left\{\begin{array}{l}{a,a≤b}\\{b,a>b}\end{array}\right.$,如1*2=1,则函数f(x)=2x*2-x的值域为( )
| A. | R | B. | (0,1] | C. | (0,+∞) | D. | [1,+∞) |
14.已知抛物线的顶点在原点,焦点在y轴上,抛物线上的点P(m,-2)到焦点的距离为5,则m的值为( )
| A. | ±4 | B. | ±2$\sqrt{5}$ | C. | ±2$\sqrt{6}$ | D. | ±5 |
12.已知定义在R上的函数f(x)为周期函数,且周期为4,若在区间[-2,2]上,f(x)=$\left\{\begin{array}{l}{{2}^{x}+2m,-2≤x≤0}\\{lo{g}_{2}x-m,0<x≤2}\end{array}\right.$,则f(2017m)=( )
| A. | -$\frac{9}{4}$ | B. | -$\frac{5}{2}$ | C. | $\frac{9}{4}$ | D. | $\frac{5}{2}$ |
11.记数列{an}的前n项和为Sn,若Sn=3an+1,则a10=( )
| A. | -$\frac{{3}^{9}}{{2}^{10}}$ | B. | -$\frac{{3}^{10}}{{2}^{10}}$ | C. | $\frac{{3}^{9}}{{2}^{10}}$ | D. | $\frac{{3}^{10}}{{2}^{10}}$ |
10.下列点在曲线x2+y2-3xy+2=0上的是( )
0 238229 238237 238243 238247 238253 238255 238259 238265 238267 238273 238279 238283 238285 238289 238295 238297 238303 238307 238309 238313 238315 238319 238321 238323 238324 238325 238327 238328 238329 238331 238333 238337 238339 238343 238345 238349 238355 238357 238363 238367 238369 238373 238379 238385 238387 238393 238397 238399 238405 238409 238415 238423 266669
| A. | $(0,\sqrt{2})$ | B. | $(\sqrt{2},0)$ | C. | $(-\sqrt{2},\sqrt{2})$ | D. | $(\sqrt{2},\sqrt{2})$ |