题目内容
求满足下列条件的直线
方程(13分)
(1)直线
过原点且与直线
的夹角为
;
(2)直线
过直线
与
的交点,且点
到
的距离为
.
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233709454280.png)
(1)直线
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233709454280.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233709501791.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233709532420.png)
(2)直线
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233709454280.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233709673687.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233709704730.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233709719537.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233709454280.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233709953386.png)
(1)
;(2)
。
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233710031725.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233710297787.png)
本题考查直线方程的求法,是基础题.解题时要认真审题,注意直线与直线垂直、直线与直线平行、直线交点等知识点的合理运用.
(1)因为直线
的倾斜角为
,由条件,直线
的倾斜角应为
或
,所以直线
的斜率
,又直线
过原点,所以直线
的方程为:
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233710031725.png)
(2)由条件设直线
为
,整理得
,点
到
的距离为![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233709953386.png)
解:(1)直线
的倾斜角为
,由条件,直线
的倾斜角应为
或
,所以直线
的斜率
,又直线
过原点,所以直线
的方程为:
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233710031725.png)
(2)由条件设直线
为
,整理得
,点
到
的距离为
,则
,解得
,所以直线
为
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233710297787.png)
(1)因为直线
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233710390314.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233709532420.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233709454280.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233710453262.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233710468413.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233709454280.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233710515576.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233709454280.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233709454280.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233710031725.png)
(2)由条件设直线
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233709454280.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233710624973.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/201408232337109361057.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233709719537.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233709454280.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233709953386.png)
解:(1)直线
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233710390314.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233709532420.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233709454280.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233710453262.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233710468413.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233709454280.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233710515576.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233709454280.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233709454280.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233710031725.png)
(2)由条件设直线
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233709454280.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233710624973.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/201408232337109361057.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233709719537.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233709454280.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233709953386.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/201408232337116541338.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233711685681.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233709454280.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823233710297787.png)
![](http://thumb.zyjl.cn/images/loading.gif)
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