解题方法
1 . 某学校举办毕业联欢晚会,舞台上方设计了三处光源.如图,
是边长为6的等边三角形,边
的中点
处为固定光源,
分别为边
上的移动光源,且
始终垂直于
,三处光源把舞台照射出五彩缤纷的若干区域.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/6/26/b6550c17-ac14-4a09-99aa-dbac9608a71b.png?resizew=170)
(1)当
为边
的中点时,求线段
的长度;
(2)求
的面积的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3cf9b288c48c73463a2f214f02b6952a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0d54431bbb28ebd98db5c1dc6083a75.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9ce6c0e9de83f2e64ae33609fc08459d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/907d5147cea4c9ce855074864fe54506.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/6/26/b6550c17-ac14-4a09-99aa-dbac9608a71b.png?resizew=170)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f68d65ed39a9dfd09c5b907b5de6b144.png)
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