题目内容
在平面直角坐标系中,规定把一个点先绕原点逆时针旋转45°,再作出旋转后的点关于原点的对称点称为一次变换.已知点A的坐标为(-1,0),把点A经过连续2013次这样的变换得到的点A2013的坐标是 .
(-
,-
)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823025453319413.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823025453319413.png)
试题分析:由题意第一次旋转后的坐标为(
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823025453319413.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823025453319413.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823025453319413.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823025453319413.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823025453319413.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823025453319413.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823025453319413.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823025453319413.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823025453475678.png)
由题意第一次旋转后的坐标为(
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823025453319413.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823025453319413.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823025453319413.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823025453319413.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823025453319413.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823025453319413.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823025453319413.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823025453319413.png)
因为
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823025453475678.png)
所以把点A经过连续2013次这样的变换得到的点A2013的坐标是(-
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823025453319413.png)
![](http://thumb.zyjl.cn/pic2/upload/papers/20140823/20140823025453319413.png)
点评:解答此类找规律的问题的关键是仔细分析题中所给的特征得到规律,再把这个规律应用于解题.
![](http://thumb.zyjl.cn/images/loading.gif)
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