13.
若一次函数y=kx+b的图象如图所示,则y<0时自变量x的取值范围是( )
| A. | x>2 | B. | x<2 | C. | x>-1 | D. | x<-1 |
11.若二次根式$\sqrt{x-1}$在实数范围内有意义,则x的取值范围是( )
| A. | x≤-1 | B. | x≥-1 | C. | x≤1 | D. | x≥1 |
10.对于两个不相等的实数a、b,我们规定符号max{a,b}表示a、b中较大的数,如:max{2,4}=4.按照这个规定.方程max{x,-x}=$\frac{2x+1}{x}$的解为( )
| A. | $1-\sqrt{2}$ | B. | $2-\sqrt{2}$ | C. | $1-\sqrt{2}$或$1+\sqrt{2}$ | D. | $1+\sqrt{2}$或-1 |
7.
如图,平行四边形ABCD的顶点C在y轴正半轴上,CD平行于x轴,直线AC交x轴于点E,BC⊥AC,连接BE,反比例函数$y=\frac{k}{x}$(x>0)的图象经过点D.已知S△BCE=2,则k的值是( )
| A. | 2 | B. | -2 | C. | 3 | D. | 4 |
6.
如图,在平行四边形ABCD中,E是AB的中点,CE和BD交于点O,设△OCD的面积为m,△OEB的面积为$\sqrt{5}$,则下列结论中正确的是( )
0 284147 284155 284161 284165 284171 284173 284177 284183 284185 284191 284197 284201 284203 284207 284213 284215 284221 284225 284227 284231 284233 284237 284239 284241 284242 284243 284245 284246 284247 284249 284251 284255 284257 284261 284263 284267 284273 284275 284281 284285 284287 284291 284297 284303 284305 284311 284315 284317 284323 284327 284333 284341 366461
| A. | m=5 | B. | m=4$\sqrt{5}$ | C. | m=3$\sqrt{5}$ | D. | m=10 |