14.已知圆的方程为x2+(y-1)2=4,若过点$P({1,\frac{1}{2}})$的直线l与此圆交于A,B两点,圆心为C,则当∠ACB最小时,直线l的方程为( )
| A. | 4x-2y-3═0 | B. | x+2y-2═0 | C. | 4x+2y-3═0 | D. | x-2y+2=0 |
10.
如图,已知正方体ABCD-A1B1C1D1棱长为8,点H在棱AA1上,且HA1=2,在侧面BCC1B1内作边长为2的正方形EFGC1,P是侧面BCC1B1内一动点且点P到平面CDD1C1距离等于线段PF的长,则当点P运动时,|HP|2的最小值是( )
0 229675 229683 229689 229693 229699 229701 229705 229711 229713 229719 229725 229729 229731 229735 229741 229743 229749 229753 229755 229759 229761 229765 229767 229769 229770 229771 229773 229774 229775 229777 229779 229783 229785 229789 229791 229795 229801 229803 229809 229813 229815 229819 229825 229831 229833 229839 229843 229845 229851 229855 229861 229869 266669
| A. | 87 | B. | 88 | C. | 89 | D. | 90 |