17.已知函数f(x)=x2+ax的图象在点A(0,f(0))处的切线l与直线2x-y+2=0平行,若数列$\left\{{\frac{1}{f(n)}}\right\}$的前n项和为Sn,则S10的值为( )
| A. | $\frac{175}{264}$ | B. | $\frac{11}{24}$ | C. | $\frac{175}{132}$ | D. | $\frac{2015}{2016}$ |
16.抛物线$x=\frac{1}{4}{y^2}$的焦点到双曲线x2-y2=2的渐近线的距离是( )
| A. | $\frac{\sqrt{2}}{2}$ | B. | $\sqrt{2}$ | C. | $\frac{1}{2}$ | D. | $\frac{{\sqrt{2}}}{32}$ |
15.已知集合M={x|x2-x-2<0},P={x|x≤a},若M∩P=∅,则实数a的取值范围是( )
| A. | {a|a<-1} | B. | {a|a≥2} | C. | {a|-1<a<2} | D. | {a|a≤-1} |
11.已知向量$\overrightarrow a$=(2,1),$\overrightarrow b$=(-1,k),若$\overrightarrow a$⊥(2$\overrightarrow a$-$\overrightarrow b$),则k=( )
0 233651 233659 233665 233669 233675 233677 233681 233687 233689 233695 233701 233705 233707 233711 233717 233719 233725 233729 233731 233735 233737 233741 233743 233745 233746 233747 233749 233750 233751 233753 233755 233759 233761 233765 233767 233771 233777 233779 233785 233789 233791 233795 233801 233807 233809 233815 233819 233821 233827 233831 233837 233845 266669
| A. | -12 | B. | 12 | C. | 6 | D. | -6 |