已知抛物线y=x2-4x与x轴交于点A,B,顶点为C,则△ABC的面积为_.
已知抛物线y=x2-4x与x轴交于点A,B,顶点为C,则△ABC的面积为______.
数学人气:308 ℃时间:2019-10-19 22:29:22
优质解答
y=0时,x
2-4x=0
解得x
1=0,x
2=4
∴线段AB的长为4
∵顶点C的纵坐
==-4
∴以AB为底的△ABC的高为4
∴S
△ABC=
×4×4=8.
我来回答
类似推荐
猜你喜欢
- 1定语从句中先行词和关系代词二合一的情况
- 2解三元一次方程组{x+2y-z=3,2x+y+z=5,3x+4y+z=10时,先消去z,得二元一次方程组_____________,再消去
- 3如图,AB为圆O的直径,CD是圆O的弦,AB,CD的延长线交于点E,已知AB=2DE,∠E=18°,求∠AOC的度数.
- 4My mother will take me to the movie if she _________ free this weekend.
- 5Albert Einstein was a great scientist(A.that B.what C.whom D.which)was considered a genious.
- 6Zn+HNO3-Zn(NO3)2+N2O+H2O
- 7观察等式:(1)9-1=2×4,(2)25-1=4×6,(3)49-1=6×8,.按照这种规律写出第n(n为正整数)个等
- 8Ordinary people know little of the time and effort it takes to read.中文意思
- 91、 (由于)the teacher's help,we finished the work on time.由于怎么写?
- 10I‘m a d___on our school football team.