2.已知抛物线y2=2px(p>0)的焦点F到准线的距离为2,若抛物线上一点P满足$\overrightarrow{PF}=2\overrightarrow{FM},|\overrightarrow{PF}$|=3,则点M的坐标为( )
| A. | ($\frac{1}{2}$,2$\sqrt{2}$)或($\frac{1}{2}$,-2$\sqrt{2}$) | B. | ($\frac{1}{2}$,$\sqrt{2}$)或($\frac{1}{2}$,-$\sqrt{2}$) | C. | (2$\sqrt{2}$,$\frac{1}{2}$)或(2$\sqrt{2}$,-$\frac{1}{2}$) | D. | ($\sqrt{2}$,$\frac{1}{2}$)或($\sqrt{2}$,-$\frac{1}{2}$) |
18.某校为全面实施素质教育,大力发展学生社团,高一年级的五名同学准备参加“文学社”、“魔术社”、“思辨社”、“公益社”四个社团,若每个社团至少有一名同学参加,每名同学必须参加且只能参加一个社团,同学甲不参加“魔术社”,同学乙与同学丙不在同一个社团,则不同参加方法的种数为( )
0 229666 229674 229680 229684 229690 229692 229696 229702 229704 229710 229716 229720 229722 229726 229732 229734 229740 229744 229746 229750 229752 229756 229758 229760 229761 229762 229764 229765 229766 229768 229770 229774 229776 229780 229782 229786 229792 229794 229800 229804 229806 229810 229816 229822 229824 229830 229834 229836 229842 229846 229852 229860 266669
| A. | 72 | B. | 162 | C. | 180 | D. | 216 |