解题方法
1 . 已知
且
,设
是空间中
个不同的点构成的集合,其中任意四点不在同一个平面上,
表示点
,
间的距离,记集合![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58a65680a7f5b5b93239c7dbdc1edd22.png)
(1)若四面体
满足:
,
,且![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce519312a849963b376c202c3f9d7cf7.png)
①求二面角
的余弦值:
②若
,求![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18c84afeae87337f9b22fa12902222d1.png)
(2)证明:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e1ef3399691fa63838aa0474d25b9dc.png)
参考公式:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5818ede14d21f6df9ef9c2bfe09286c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a37a59558292ad6b3d0978bfd7484990.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5ebfda261c4a27e1fa2ee5fc6d4bdfb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58a65680a7f5b5b93239c7dbdc1edd22.png)
(1)若四面体
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95c12f98844971f91baaeed4775a72e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bd6a2b112facda441f4e34bf5c145fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce519312a849963b376c202c3f9d7cf7.png)
①求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c2898853a3396f0878af9eac934416d.png)
②若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e10e0b10442a269fe929eb8e592cb1ef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18c84afeae87337f9b22fa12902222d1.png)
(2)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e1ef3399691fa63838aa0474d25b9dc.png)
参考公式:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c27d71b7260e008ebefdb79da3a2f3e4.png)
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2 . 设
为互不相同的实数,将它们依如下规则填入100×100的方格中:在第i行和第j列相交处的方格内填入数字
.已知每一列的所有数字乘积都等于1,证明:每一行的所有数的乘积都等于
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fdf8dc0ff13d9bce6c461ba8da2b77be.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf4efe69158ae673f8d6740bcd940bc0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acbc6a613224461ade69362d46550474.png)
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3 . 有n个不同的物体,从中允许重复地选取r个物体的方法数为
.为了对比,我们用两种方法来证明.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ffc30477c8d66971221b57eeb325ed4.png)
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4 . 已知数列
满足
,
,
.
(1)猜想数列
的单调性,并证明你的结论;
(2)证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e976c0663fa749ca749f99842d21ca03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/195fc747e2fc50cb6df2c844d51e4d80.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d8c7493005191506bf32b9e39a5a4c0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/deda945164283569437cda6976fe35ea.png)
(1)猜想数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d497e59ca415b9973ae8b07cd28e472.png)
(2)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5825807d5e23919ae8dcd6751db947d9.png)
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5 . 证明:
(
且
).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/89acdb8232fe9ed19439fdc15c8f4070.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c4591f545ee3ce704391e55da4ad940d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/856b137a34d2d5b20671b7a3c7a29606.png)
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2023高三·全国·专题练习
6 . 求证:
,
表示
的整数部分.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/afe14b11286183bf737abe4d2afb6a7b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d48c4bc413627423fa8eef06b4e53c03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d500215f72c2fbc10ba0f6e15c4165ff.png)
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7 . 证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/87fdd85b89b393f094f0418e72f05c3f.png)
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2023高三·全国·专题练习
8 . 证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a930e6e92034b0e479870cf9574b8f4.png)
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2023高三·全国·专题练习
9 . 设α,β为非零实数,证明恒等式
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14a0719c918b75538eb29330d8a7b274.png)
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