1 . (1)如图,平行四边形
中,对角线
与
交于
点,
为平面内任意一点. 求证:
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/22/322ac58b-6ace-4b65-b19a-550448e8f281.png?resizew=207)
(ⅰ)
;
(ⅱ)
;
(2)矩形
中,
为平面内任意一点.求证:
;
(3)在平面上,
,
,
.若
,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/22/322ac58b-6ace-4b65-b19a-550448e8f281.png?resizew=207)
(ⅰ)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62f7667168e00e009966f8772298b797.png)
(ⅱ)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c58014648a1d8377acfdf244ee07e400.png)
(2)矩形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca8ea92bb22eff6ace44566715890c99.png)
(3)在平面上,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61a20f65d50ced816b828d472d9f0ac6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d8db0b0d865a43ff70c7dbbd7d2b978.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67b15fdbdcfd47d81f23245bd02d9346.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/779d07a49f3439c69cb9e76bad784fb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e578668ad5d0ad2b240ac6906c66f2c.png)
您最近一年使用:0次
名校
2 . 如图,在
的边上各自做匀速运动的点D,E,F,当
时分别从点A,B,C出发,以各自的 定速度向点B,C,A前进,当
时分别到达点B,C,A.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/28/ef2d4b5f-0f3c-4fac-8d1b-0b38bda26f6f.png?resizew=142)
(1)证明:在运动过程中
的重心保持不变;
(2)若
的面积为S,求
的面积的最小值
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7aeb9a94e392f6759b18abed89aacc5e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a2a51944c720568f35d443589dfc1aa.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/28/ef2d4b5f-0f3c-4fac-8d1b-0b38bda26f6f.png?resizew=142)
(1)证明:在运动过程中
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fe6f083d01de5d6212394f67dc517e20.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72cb97395ebc5ee1b212afb7a97b985c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a1d336e14788f6f1d303b06965b19f94.png)
您最近一年使用:0次
2021-03-23更新
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363次组卷
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3卷引用:天津市南开中学2020-2021学年高一下学期3月月考数学试题