4.抛物线y=-2(x+3)2是由抛物线y=-2x2向( )平移( )个单位得到的.
| A. | 左、3 | B. | 右、3 | C. | 上、3 | D. | 下、3 |
3.已知两个数的和是-7,积是6,则这两个数是( )
| A. | -4和-3 | B. | 4和3 | C. | 6和1 | D. | -6和-1 |
1.
如图,在△ABC中,AB=5,AC=3,则BC边上的中线AD的取值范围是( )
| A. | 2<AD<8 | B. | 0<AD<8 | C. | 1<AD<4 | D. | 3<AD<5 |
19.若关于x的函数y=kx2+2x-1与x轴仅有一个公共点,则实数k的值为( )
0 297627 297635 297641 297645 297651 297653 297657 297663 297665 297671 297677 297681 297683 297687 297693 297695 297701 297705 297707 297711 297713 297717 297719 297721 297722 297723 297725 297726 297727 297729 297731 297735 297737 297741 297743 297747 297753 297755 297761 297765 297767 297771 297777 297783 297785 297791 297795 297797 297803 297807 297813 297821 366461
| A. | -1 或0 | B. | 1 | C. | 0 | D. | -1 |