1.
函数y1=$\frac{k}{x}$与y2=ax+b的图象在同一直角坐标系中如图所示,当y1<y2时,x的取值范围是( )
| A. | 1<x<3 | B. | x<1 | C. | x<0或1<x<3 | D. | x<1或x>3 |
20.
如图,平行四边形ABCD,点E在边BC上,点F在AD边的延长线上,且EF∥BD,EF,CD交于点G,$\frac{DF}{AD}$=$\frac{2}{5}$,S四边形BDGE=a,则S平行四边形ABCD的值为( )
| A. | $\frac{25a}{8}$ | B. | $\frac{25a}{9}$ | C. | $\frac{25a}{16}$ | D. | $\frac{16a}{9}$ |
19.若a+b=-6,ab=6,则$\sqrt{\frac{b}{a}}$+$\sqrt{\frac{a}{b}}$的值为( )
| A. | $\sqrt{6}$ | B. | -$\sqrt{6}$ | C. | 2$\sqrt{3}$ | D. | -2$\sqrt{3}$ |
18.关于x的方程(k-1)x2+4x-1=0有两个不相等的实数根,则k的取值范围是( )
| A. | k>-3 | B. | k<5 | C. | k>-3且k≠1 | D. | k<5且k≠1 |
17.下列函数中,y关于x的二次函数的是( )
0 297206 297214 297220 297224 297230 297232 297236 297242 297244 297250 297256 297260 297262 297266 297272 297274 297280 297284 297286 297290 297292 297296 297298 297300 297301 297302 297304 297305 297306 297308 297310 297314 297316 297320 297322 297326 297332 297334 297340 297344 297346 297350 297356 297362 297364 297370 297374 297376 297382 297386 297392 297400 366461
| A. | y=x3+2x2+3 | B. | y=-$\frac{1}{{x}^{2}}$ | C. | y=x2+x | D. | y=mx2+x+1 |