A.当x<1时,y随x的增大而减小 |
B.它的图象与x轴有交点 |
C.当1<x<3时,y>0 |
D.顶点坐标为(2,-1) |
b |
2a |
4ac-b2 |
4a |
A.直线x=-1 | B.直线x=1 | C.直线x=-2 | D.直线x=2 |
A.xy+x2=1 | B.x2-y+2=0 | C.y=
| D.y2-4x=3 |
A.(-2,3) | B.(2,3) | C.(-2,-3) | D.(2,-3) |
A.y=x(x+1)+
| B.y=x2 | ||
C.y=2x3+x2+1 | D.y=33x-1 |
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