1 . 已知A,B,C,P为空间内不共线的四点,G为
的重心.
(1)证明:
;
(2)若向量
,
,
的模长均为2,且两两夹角为
,求
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb74becf9bdf4d13e122ac50180e1f57.png)
(2)若向量
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/454a02d14e3371707f979ea0cd7b9412.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee2638bcdc57e4e56a9b61430c9edfbf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7b683529d8299e73e36ef06d0b1463d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac1a63ab608517bb10aa036783dfb51f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d7dcb895ec70ebe01260e881414b4e1.png)
您最近一年使用:0次
2 . 在正四面体OABC中,E,F,G,H分别是OA,AB,BC,OC的中点.设
,
,
.
(1)用
,
,
表示
,
;
(2)用向量方法证明:E,F,G,H四点共面.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14390e9b6b44472bdc7a131133ab39b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87cd14dfc0024459f9d8e594c95c5106.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e07dcf0b16163e0e0e0c0f248466ee7e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/11/8/3d7b3045-39ae-4d68-a19b-b247708dab16.png?resizew=189)
(1)用
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64c5562bd4d1b54424330cb6329cd79d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b45ba716f03748c19b7ce2f99af536ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73a0b19e69be46452425916a0fcb49c9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae54940f33b8714da5fe3b7546f8b3dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e74c0f207612e015857b78b99db483e4.png)
(2)用向量方法证明:E,F,G,H四点共面.
您最近一年使用:0次
2023-10-20更新
|
109次组卷
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2卷引用:江西省上饶市广信中学2023-2024学年高二上学期11月月考数学试题