9.若正比例函数y=3x的图象经过A(m,4m+1),则m的值为( )
| A. | 1 | B. | -1 | C. | $\frac{2}{5}$ | D. | -$\frac{2}{5}$ |
5.
如图,分别过点P(i,0)(i=1、2、…n)作x轴的垂线,交y=$\frac{1}{2}$x2的图象于点A,交直线y=-$\frac{1}{2}$x于点Bi,则$\frac{1}{{A}_{1}{B}_{1}}$+$\frac{1}{{A}_{2}{B}_{2}}$+…+$\frac{1}{{A}_{n}{B}_{n}}$等于( )
| A. | $\frac{2n}{n}$ | B. | $\frac{2n}{n+1}$ | C. | $\frac{2n}{n-1}$ | D. | $\frac{n}{n-1}$ |
3.下列函数中,其图象与x轴有两个交点的是( )
0 285899 285907 285913 285917 285923 285925 285929 285935 285937 285943 285949 285953 285955 285959 285965 285967 285973 285977 285979 285983 285985 285989 285991 285993 285994 285995 285997 285998 285999 286001 286003 286007 286009 286013 286015 286019 286025 286027 286033 286037 286039 286043 286049 286055 286057 286063 286067 286069 286075 286079 286085 286093 366461
| A. | y=8(x+2015)2+2016 | B. | y=8(x-2015)2+2016 | ||
| C. | y=-8(x-2015)2-2016 | D. | y=-8(x+2015)2+2016 |