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科目:高中数学
来源:不详
题型:解答题
已知平面直角坐标系内三点
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824041840727300.png)
、
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824041840743309.png)
、
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824041840758312.png)
在一条直线上,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824041840789727.png)
,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824041840805639.png)
,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824041840821644.png)
,且
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824041840836536.png)
,其中
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824041840836292.png)
为坐标原点.
(1)求实数
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824041840867337.png)
,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824041840883297.png)
的值;
(2)设
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824041840899537.png)
的重心为
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824041840914316.png)
,若存在实数
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824041840930323.png)
,使
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824041840945631.png)
,试求
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824041840961516.png)
的大小.
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科目:高中数学
来源:不详
题型:单选题
在四边形
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824051709953514.png)
中,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824051709969723.png)
,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824051709984710.png)
,则该四边形的面积为( ).
A.![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824051710000406.png) | B.![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824051710016391.png) | C.5 | D.15 |
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科目:高中数学
来源:不详
题型:单选题
在△ABC中,点D在CB的延长线上,且
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824044527311502.png)
,则s+r等于( )
A.0 |
B.![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824044527327256.png) |
C.![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824044527327253.png) |
D.3 |
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科目:高中数学
来源:不详
题型:单选题
在平面直角坐标系
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824043648033413.png)
中,点
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824043648111545.png)
和点
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824043648127540.png)
满足:向量
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824043648143381.png)
在向量
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824043648174394.png)
上的投影为
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824043648174390.png)
,则
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824043648189431.png)
的值为( )
A.5 | B.![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824043648221416.png) | C.8 | D.![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824043648236414.png) |
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科目:高中数学
来源:不详
题型:单选题
在平面斜坐标系
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824043121197465.png)
中,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824043121213266.png)
轴方向水平向右,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824043121228310.png)
方向指向左上方,且
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824043121260801.png)
,平面上任一点
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824043121275289.png)
关于斜坐标系的斜坐标是这样定义的:若
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824043121275738.png)
(其中向量
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824043121291435.png)
分别是与
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824043121213266.png)
轴、
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824043121228310.png)
轴同方向的单位向量),则
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824043121275289.png)
点斜坐标为
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824043121447499.png)
,那么以
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824043121462292.png)
为顶点,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824043121462507.png)
为焦点,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824043121213266.png)
轴为对称轴的抛物线方程为
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科目:高中数学
来源:不详
题型:单选题
在
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824040719599495.png)
所在的平面内,点
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824040719614439.png)
满足
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824040719630469.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824040719661312.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824040719677407.png)
,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824040719692641.png)
,且对于任意实数
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824040719708297.png)
,恒有
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824040719739575.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824040719755601.png)
,则 ( )
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科目:高中数学
来源:不详
题型:单选题
如图,在△ABC中,BD=2DC.若
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824045600454417.png)
,
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824045600470426.png)
,则
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824045600470321.png)
=( )
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/201408240456005011982.png)
A.
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824045600517472.png)
B.
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824045600532500.png)
C.
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824045600548477.png)
D.
![](http://thumb.zyjl.cn/pic2/upload/papers/20140824/20140824045600563502.png)
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