2.
在长方体ABCD-A1B1C1D1中,AA1=6,AB=3,AD=8,点M是棱AD的中点,N在棱AA1上,且满足AN=2NA1,P是侧面四边形ADD1A1内一动点(含边界),若C1P∥平面CMN,则线段C1P长度最小值是( )
| A. | $\sqrt{17}$ | B. | 4 | C. | $\sqrt{15}$ | D. | 3 |
1.已知点$M({-6,3\sqrt{5}})$在双曲线$C:\frac{x^2}{a^2}-\frac{y^2}{b^2}=1({a>0,b>0})$的渐近线上,C的焦距为12,则C的方程为( )
| A. | $\frac{x^2}{8}-\frac{y^2}{10}=1$ | B. | $\frac{x^2}{10}-\frac{y^2}{8}=1$ | C. | $\frac{x^2}{16}-\frac{y^2}{20}=1$ | D. | $\frac{x^2}{20}-\frac{y^2}{16}=1$ |
20.若x,y满足约束条件$\left\{\begin{array}{l}3x-4≥0\\ y-1≥0\\ 3x+y-6≤0\end{array}\right.$,则z=2x+y的最大值为( )
| A. | $\frac{11}{3}$ | B. | $\frac{13}{3}$ | C. | $\frac{14}{3}$ | D. | 5 |
17.若数列{an}满足a1+2a2+3a3+…+nan=n2(n∈N*),则a7=( )
0 240616 240624 240630 240634 240640 240642 240646 240652 240654 240660 240666 240670 240672 240676 240682 240684 240690 240694 240696 240700 240702 240706 240708 240710 240711 240712 240714 240715 240716 240718 240720 240724 240726 240730 240732 240736 240742 240744 240750 240754 240756 240760 240766 240772 240774 240780 240784 240786 240792 240796 240802 240810 266669
| A. | $\frac{9}{5}$ | B. | $\frac{11}{6}$ | C. | $\frac{13}{7}$ | D. | 2 |