在直角坐标系中,有矩形ABCD,AB=4,BC=8,原点O是BC的中点,且沿对角线AC翻折△ACD,AD'与BC交于点点E(1)求点E的坐标:(2)求重合部分的面积(3)若过D E两点的直线与Y轴 交于点F,求点F的坐标.图在
来源:学生作业帮助网 编辑:作业帮 时间:2024/08/29 03:55:54
在直角坐标系中,有矩形ABCD,AB=4,BC=8,原点O是BC的中点,且沿对角线AC翻折△ACD,AD'与BC交于点点E(1)求点E的坐标:(2)求重合部分的面积(3)若过D E两点的直线与Y轴 交于点F,求点F的坐标.图在
在直角坐标系中,有矩形ABCD,AB=4,BC=8,原点O是BC的中点,且沿对角线AC翻折△ACD,AD'与BC交于点点E
(1)求点E的坐标:
(2)求重合部分的面积
(3)若过D E两点的直线与Y轴 交于点F,求点F的坐标.
图在下面
在直角坐标系中,有矩形ABCD,AB=4,BC=8,原点O是BC的中点,且沿对角线AC翻折△ACD,AD'与BC交于点点E(1)求点E的坐标:(2)求重合部分的面积(3)若过D E两点的直线与Y轴 交于点F,求点F的坐标.图在
BC在x轴上,还是在y轴上?AB在BC上方还是下方?很重要!
不好意思,这么久才回来看 估计你们老师已经讲过了吧!不过我会尽力的
(1)由题意知 △ADC≌△AD'C≌△ABC B(-4,0)
∴∠ACB=∠DAC
∴△ACE是等腰三角形(等角对等边)
∴AE=CE △ABE≌△DCE
设BE长为x,则有方程 x^2 + 4^2 = (8 - x)^2
[因为是长方形嘛,所以∠B是直角,△ABE是直角三角形,用勾股定理上就好了]
解得x=3
∵BC在x轴上∴点E纵坐标为0 ∴点E坐标为(-1,0)
(2)S△AEC=S△ABC-△ABE
S△ABC=1/2 S长方形ABCD = 4×8÷2 = 16
S△ABE=1/2 BE×AB = 3×4÷2 = 6
∴S△AOC=16-6=10
(3)由题意知 D(4,4)
由(1)知点E坐标为 (-1,0)
设此直线的解析式为 y=kx+b
将两点坐标带入,得方程组 4 = 4k + b ①
0 = -k + b ②
解得,此直线的解析式为 y = 4/5 k + 4/5
一次函数直线交y轴于(0,b)点
∴点F坐标为(0,4/5)
是中考复习题吗?去年这时候我也成天在做这种高综合性题目,现在很希望可以帮到你们啊——
如果这道题还有不懂,就来问我好了!
墨雨烟兄弟 BC在X轴上 AB⊥BC AB在Y轴左边 图在这里 我也不会写 麻烦你帮帮忙哈
Nike Kobe V Bruce Lee,Dunk low men shoes
Inspired by Bruce Lee’,women gucci low top sneakers;s bright yellow outfit in the movie Game of Death, these Nike Zoom Kobe V Bruce Lee editions have poppe...
全部展开
Nike Kobe V Bruce Lee,Dunk low men shoes
Inspired by Bruce Lee’,women gucci low top sneakers;s bright yellow outfit in the movie Game of Death, these Nike Zoom Kobe V Bruce Lee editions have popped up on several occasions. Well I bring news of joy and happiness for those Kobe/Bruce Lee fans out there. These will be available at House of Hoops locations all over the country on January 16. On a side note,cheap air jordans, Bruce Lee fights Laker legend Kareem Abdul Jabar in this movie and if I recall, he kicks his ass defeats him. [via FL]
Bruce Lee
Also you will like it:
Nike Zoom Bruin SB Green Leaf
Ralph Lauren Solid Polos Nike Global Design DIrect
mens gucci low top sneakers Vans Vault 2010 Standa
收起