如图,某数学兴趣小组通过“画板”探究一个图形,
,
为
两边上的动点,分别作
和
的平分线交于点
,作
和
的平分线交于点
.经小组成员交流后,证明了点
,
,
,
在同一个圆上.
在进一步探究时,动态调整点
,
的位置,成员小敏发现,无论
(图①),还是
(图②),点
,
,
,
所在的圆均明显与
的两边有四个交点,只有当
时(图③),点
,
,
,
所在的圆可能与
的两边仅各有一个交点.于是,小敏猜想:当
时(图③),点
,
,
,
所在的圆与
的两边相切.
请你判断这个猜想是否正确,如果正确,请证明;如果不正确,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/febc9a89d0d1c97b88c0f4acd32b4e67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d3e081637bcea5368cc72370bae283b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eb3de20ba8bda63c650ef571be155702.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23dc2d2dd56fcc67698c45a6e0e48f80.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d8a71e8a816d9ef65d4bffd81fd53216.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
在进一步探究时,动态调整点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ab132ec1b521e1646193b1deeac569f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4eaba52573daad58e794a319774bf800.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/febc9a89d0d1c97b88c0f4acd32b4e67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a55b6ce55e67f6e95e616eaf1ca3f6f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/febc9a89d0d1c97b88c0f4acd32b4e67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a55b6ce55e67f6e95e616eaf1ca3f6f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/febc9a89d0d1c97b88c0f4acd32b4e67.png)
请你判断这个猜想是否正确,如果正确,请证明;如果不正确,请说明理由.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/19/2be0f249-89dc-4578-a900-a32b2790fbae.png?resizew=484)
更新时间:2022-06-19 14:22:32
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解题方法
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【推荐1】如图,AB是
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(1)求证:AC是
的切线;
(2)若点E是
的中点,AE与BC交于点F;
①求证:
;
②当
,
时,请直接写出BF的长为______.
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【推荐1】如图,AB是⊙O的直径,点C是⊙O上一点,∠CAB的平分线AD交
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(1)求证:∠ADE=∠FBD;
(2)求证:DE是⊙O的切线;
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【推荐2】如图,在△ABC中,AB=AC,以AB为直径的⊙O分别交BC于点D,交CA的延长线于点E,过点D作DH⊥AC,垂足为点H,连接DE,交AB于点F.
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