如图，已知二次函数y=ax2+bx+c(a#0)的图象如图所示，给出以下四个结论：①abc=0，②a+b+c>0，③b=3a, ④4ac—b2<0；其中正确的结论有

题干

如图，已知二次函数y=ax²+bx+c(a#0)的图象如图所示，给出以下四个结论：

①abc=0，②a+b+c>0，③b=3a, ④4ac—b²<0；其中正确的结论有（）

A：1个

B：2个

C：3个

D：4个

上一题下一题 0.0难度选择题更新时间:2020-01-11 05:31:02

答案(点此获取答案解析）

C

同类题4

Mike is a middle school student. He goes to school from Monday to Friday. His home is about 5 miles from school. He usually walks to school. It takes him 30 minutes to walk there. Nancy's home is a little farther. It's 20 miles from school. So she often takes the school bus. It takes her 15 minutes to get to school. Bob lives outside the city. It's a town 30 miles away from his school. He takes the subway. It takes him 8 minutes to get to school by subway. He can have breakfast at home and then leave for the subway station. He studies very hard.

Name	How	How far	How long
Mike	He ____	It’s about 5 miles from school	____
____	She takes the school bus	It’s____ from school	15 minutes
Bob	He ____	It’s 30 miles from his school	20 minutes

题干

答案(点此获取答案解析）

同类题1

同类题2

同类题3

同类题4

同类题5