1 . 已知,
.
(1)求
,
在
上的投影;
(2)证明
三点共线,并在
时,求
的值;
(3)求
的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/062b00cb0fea7c3ec742e3e04cff0810.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3ace585d3cc2e113a0927cdf9e56756a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d60dcb171bb7fd972aab8294d63acdb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f68628a408537b1cf3bf1ca2a69731b6.png)
(2)证明
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24e0c10fb103930eabd5fa18e8f9bb06.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0f134605b8b48aaebce5ebfc06b7467.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
(3)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dce2c46509372408074cbf9c7d30b660.png)
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2 . 在平面直角坐标系中,O为坐标原点,A、B、C三点满足
.
求证:A、B、C三点共线;
已知
、
,
,
的最小值为5,求实数m的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/431d15b80cc65e037b35bc10bd8d45e7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4141b26d2c32655003494a91ad6331b5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/65863c1abad833b79c303bfca24f535c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6611c73064bda197766c00b448dd0030.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/02f8c513fdf6f75cdd4f441e35ecfc04.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a848eab8a7cd5094a8dc37f9b91f38b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/26a39a25091e39b138526e12a3937872.png)
您最近一年使用:0次
2018-03-02更新
|
1941次组卷
|
9卷引用:湖北省宜昌市第二中学2018-2019学年高一下学期期中数学试题