1 . 已知圆
上动点
,过点
作圆
的一条切线,切点为
,则
的最小值为_________ .
![](https://img.xkw.com/dksih/QBM/2016/1/27/1572469458558976/1572469464457216/STEM/d86d72e0f7714401a7a45470aeb45472.png?resizew=215)
![](https://img.xkw.com/dksih/QBM/2016/1/27/1572469458558976/1572469464457216/STEM/305b39ad68994b17a22182a0da0dd93d.png?resizew=16)
![](https://img.xkw.com/dksih/QBM/2016/1/27/1572469458558976/1572469464457216/STEM/305b39ad68994b17a22182a0da0dd93d.png?resizew=16)
![](https://img.xkw.com/dksih/QBM/2016/1/27/1572469458558976/1572469464457216/STEM/34e3b762a818487ca0b64fad32425871.png?resizew=16)
![](https://img.xkw.com/dksih/QBM/2016/1/27/1572469458558976/1572469464457216/STEM/73fbf474552a4c87a21c1d2aa4e8e1c4.png?resizew=16)
![](https://img.xkw.com/dksih/QBM/2016/1/27/1572469458558976/1572469464457216/STEM/d21fcc3457a448abbd66bf7e50d04c4b.png?resizew=29)
您最近一年使用:0次
2 . 设点
,若在圆
:
上存在点
,使得
,则
的取值范围是______ .
![](https://img.xkw.com/dksih/QBM/2016/11/11/1573141053112320/1573141058641920/STEM/f6149ab9153849d0a53b0c610a25ad18.png?resizew=53)
![](https://img.xkw.com/dksih/QBM/2016/11/11/1573141053112320/1573141058641920/STEM/2fb0a5516765459ebb2b586b790cc726.png?resizew=16)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f240cccaf24af8a796abb95cb42be52e.png)
![](https://img.xkw.com/dksih/QBM/2016/11/11/1573141053112320/1573141058641920/STEM/7aa1b9b7c6344ce7aab991d95ffa303c.png?resizew=19)
![](https://img.xkw.com/dksih/QBM/2016/11/11/1573141053112320/1573141058641920/STEM/fadde34c030f451db4716542fba9dad1.png?resizew=91)
![](https://img.xkw.com/dksih/QBM/2016/11/11/1573141053112320/1573141058641920/STEM/6ca1623f6abf4410b19bd1f65bc060b8.png?resizew=17)
您最近一年使用:0次
3 . 已知直线
与圆
:
相交于
,
两点,且△
是直角三角形,则实数![](https://staticzujuan.xkw.com/quesimg/Upload/formula/380bbacf854e30e2e747fc286d2b9997.png)
________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e870d78820ec963bac98e3590450038.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74fc2dd9f226f3e150aa1524dadbee6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/380bbacf854e30e2e747fc286d2b9997.png)
您最近一年使用:0次
4 . 已知圆
,直线
.圆C上任意一点A到直线l的距离小于2的概率为_____ .
![](https://img.xkw.com/dksih/QBM/2016/2/23/1572493558308864/1572493564280832/STEM/c722c29c783c4c6d81e7c19a58347710.png?resizew=101)
![](https://img.xkw.com/dksih/QBM/2016/2/23/1572493558308864/1572493564280832/STEM/59f3ae1ecab94bdaa8e768b8d0cf042c.png?resizew=99)
您最近一年使用:0次