2010·黑龙江哈尔滨·一模
解题方法
1 . 已知圆
与圆
,在下列说法中:
①对于任意的
,圆
与圆
始终相切;
②对于任意的
,圆
与圆
始终有四条公切线;
③当
时,圆
被直线
截得的弦长为
;
④
分别为圆
与圆
上的动点,则
的最大值为4.
其中正确命题的序号为______ .
![](https://img.xkw.com/dksih/QBM/2010/4/7/1576715455873024/1576715601297408/STEM/931d726a0d4841ae9b1c03168c628d0a.png?resizew=220)
![](https://img.xkw.com/dksih/QBM/2010/4/7/1576715455873024/1576715601297408/STEM/5635d69a619847ba9aaf57794e9012c0.png?resizew=91)
①对于任意的
![](https://img.xkw.com/dksih/QBM/2010/4/7/1576715455873024/1576715601297408/STEM/8369f20c30374e03a6b13f5d8f948a15.png?resizew=13)
![](https://img.xkw.com/dksih/QBM/2010/4/7/1576715455873024/1576715601297408/STEM/da9f02d104994c8485f6d4b5cd086f65.png?resizew=19)
![](https://img.xkw.com/dksih/QBM/2010/4/7/1576715455873024/1576715601297408/STEM/bdbc8b7398634450a3ff71a521b58b72.png?resizew=20)
②对于任意的
![](https://img.xkw.com/dksih/QBM/2010/4/7/1576715455873024/1576715601297408/STEM/8369f20c30374e03a6b13f5d8f948a15.png?resizew=13)
![](https://img.xkw.com/dksih/QBM/2010/4/7/1576715455873024/1576715601297408/STEM/da9f02d104994c8485f6d4b5cd086f65.png?resizew=19)
![](https://img.xkw.com/dksih/QBM/2010/4/7/1576715455873024/1576715601297408/STEM/bdbc8b7398634450a3ff71a521b58b72.png?resizew=20)
③当
![](https://img.xkw.com/dksih/QBM/2010/4/7/1576715455873024/1576715601297408/STEM/508345b0c6764b6d9d64ccd1991cf101.png?resizew=40)
![](https://img.xkw.com/dksih/QBM/2010/4/7/1576715455873024/1576715601297408/STEM/da9f02d104994c8485f6d4b5cd086f65.png?resizew=19)
![](https://img.xkw.com/dksih/QBM/2010/4/7/1576715455873024/1576715601297408/STEM/f15d3415524749a3ad5ff841d4133fd6.png?resizew=105)
![](https://img.xkw.com/dksih/QBM/2010/4/7/1576715455873024/1576715601297408/STEM/d6b1859244b4448a8674dc717d67ed9a.png?resizew=23)
④
![](https://img.xkw.com/dksih/QBM/2010/4/7/1576715455873024/1576715601297408/STEM/02dccdc836cd4166996e9f20863e52e3.png?resizew=31)
![](https://img.xkw.com/dksih/QBM/2010/4/7/1576715455873024/1576715601297408/STEM/da9f02d104994c8485f6d4b5cd086f65.png?resizew=19)
![](https://img.xkw.com/dksih/QBM/2010/4/7/1576715455873024/1576715601297408/STEM/bdbc8b7398634450a3ff71a521b58b72.png?resizew=20)
![](https://img.xkw.com/dksih/QBM/2010/4/7/1576715455873024/1576715601297408/STEM/67ece29fd5b54627952aefe0fdad7421.png?resizew=35)
其中正确命题的序号为
您最近一年使用:0次