13.若点(x1,y1),(x2,y2),(x3,y3)都是反比例函数y=$\frac{1}{x}$图象上的点,并且y1<0<y2<y3,则下列各式中正确的是( )
| A. | x1<x2<x3 | B. | x1<x3<x2 | C. | x2<x1<x3 | D. | x2<x3<x1 |
12.多项式x2-9与多项式x2+6x+9的公因式为( )
| A. | x-3 | B. | (x+3)2 | C. | x+3 | D. | (x-3)(x+3)2 |
11.
图中圆柱的主视图与俯视图如图所示,一只蚂蚁从A点沿着圆柱的侧面爬行到B点的最短路线长为( )
| A. | (6+4π)cm | B. | 2$\sqrt{9+{π}^{2}}$cm | C. | 7πcm | D. | 5πcm |
7.某班一小组7名同学的毕业升学体育测试成绩(满分50分)依次为:45,43,45,47,40,45,这组数据的中位数和众数分别是( )
0 284720 284728 284734 284738 284744 284746 284750 284756 284758 284764 284770 284774 284776 284780 284786 284788 284794 284798 284800 284804 284806 284810 284812 284814 284815 284816 284818 284819 284820 284822 284824 284828 284830 284834 284836 284840 284846 284848 284854 284858 284860 284864 284870 284876 284878 284884 284888 284890 284896 284900 284906 284914 366461
| A. | 43 45 | B. | 43 43 | C. | 45 45 | D. | 43 43 |