13.正方形的四个顶点A(-1,-1),B(1,-1),C(1,1),D(-1,1).抛物线y2=2px过C点.若将质点P(x,y)投入到正方形ABCD中,则y2<2px的概率为( )
| A. | $\frac{1}{6}$ | B. | $\frac{1}{3}$ | C. | $\frac{4}{3}$ | D. | $\frac{2}{3}$ |
11.已知椭圆$\frac{{x}^{2}}{2{m}^{2}}$+$\frac{{y}^{2}}{{n}^{2}}$=1和双曲线$\frac{{x}^{2}}{{m}^{2}}$-$\frac{{y}^{2}}{{n}^{2}}$=1有公共焦点,则双曲线的渐近线方程是( )
| A. | x=±$\frac{\sqrt{15}}{2}$y | B. | y=±$\frac{\sqrt{15}}{2}$x | C. | x=±$\frac{\sqrt{2}}{2}$y | D. | y=±$\frac{\sqrt{2}}{2}$x |
4.定义$\frac{n}{{p}_{1}+{p}_{2}+…+{p}_{n}}$为n个正数p1,p2…pn的“平均倒数”.若已知数列{an}的前n项的“平均倒数”为$\frac{1}{2n+1}$,又bn=$\frac{{a}_{n}+1}{4}$,则$\frac{1}{{b}_{1}{b}_{2}}$+$\frac{1}{{b}_{2}{b}_{3}}$+…+$\frac{1}{{b}_{2017}{b}_{2018}}$等于( )
0 230536 230544 230550 230554 230560 230562 230566 230572 230574 230580 230586 230590 230592 230596 230602 230604 230610 230614 230616 230620 230622 230626 230628 230630 230631 230632 230634 230635 230636 230638 230640 230644 230646 230650 230652 230656 230662 230664 230670 230674 230676 230680 230686 230692 230694 230700 230704 230706 230712 230716 230722 230730 266669
| A. | $\frac{2018}{2019}$ | B. | $\frac{2017}{2018}$ | C. | $\frac{2016}{2017}$ | D. | $\frac{2015}{2016}$ |