1 . 如图四棱台
中,
,
平面
,
.
;
(2)若
,
,
,求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ae1e04eeb4de72e5750dae77bcb6f88a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a8bfe2553e852df73185d017c0a62fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3fa6ea683971fa8b6299d7aab6d04092.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b226725af7cb49dd73896e34d99db8a2.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/462b1c65b1b233ab98a90c164c0968c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55c24a968c73e960698a572ab01e3698.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74361343159d1640b4d30317b58f8d6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f9c6ee40dff32baf8ffbf3cd4562c25a.png)
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2 . 平均值不等式是最基本的重要不等式之一,在不等式理论研究和证明中占有重要的位置,基本不等式
就是最简单的平均值不等式.一般地,假设
为n个非负实数,它们的算术平均值记为
(注:
),几何平均值记为
亦(注:
),算术平均值与几何平均值之间有如下的关系:
,即
,当且仅当
时等号成立,上述不等式称为平均值不等式,或简称为均值不等式.
(1)已知
,求
的最小值;
(2)已知正项数列
,前n项和为
.
(i)当
时,求证:
;
(ii)求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb90c316d8a99694396de80ed0b0cf25.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f2b043b989216035c6fd985f1dd6a3f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62039675c3c14eb40435c837baac504b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/616f78142aa5d339a92737356cb5f034.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3381745623cb1a441da9c0d591eb5fa8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7cdd81b8b615961adae7ec165aacfad.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/434d0c6ca47b1b7af2f3ff0b7663d908.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3c294bd0c22262b46c1ba57f8f1dc8c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01cc4e11e7cd0174262dfe66662a6a33.png)
(1)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d229cbec798c9c278a9b5979cb38247.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/59149e37a56078d30e6e734fde3d6f5f.png)
(2)已知正项数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
(i)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d72bba8881efc02361163a97c6dde32.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9021d923afeecdbb8c55e283c26704a.png)
(ii)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/237e3090bb2c02d7b62fa5d3d41b63b5.png)
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解题方法
3 . 已知数列
的前n项积为
,
,
且
.
(1)求
的通项公式;
(2)若存在m,使得
恒成立,求m的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1ae9a3b0b7aeb1545b65d91aa371b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/780a1b00ea3a4fec3069509041c84511.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d38ac38efc5f58e833f21c725e9711c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7155f9f69240c0542e3a168d3b76f917.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)若存在m,使得
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d2d74a8d73ab1ba29882f24328be243.png)
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4 . 已知数列
满足
,
,令
.
(1)求证:数列
为等差数列;
(2)设
,数列
的前n项和为
,定义
为不超过x的最大整数,例如
,
,求数列
的前n项和
.(参考公式:
)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b065334d8f60c49f4bd3d9f1373fe4cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e89bddd9c021a9caccc72cd0189e1ceb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2e5fc0b571e6545e133d36af338733b6.png)
(1)求证:数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5f0c1d9900e8c040d86a68deecb4a73d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ef6d44448092ebdb9e4a49d866a749.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ddad3d9fdb5e9951b6a1c31f9a72a71.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c4f5908d6a1217e493ed7586b6964dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc995d4dc915fce7b9aa2a580a250d1a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/50b3bdab0058f097f736bbcb844442f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37c04c237a58b94d06952c208e18a5cd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29a2b1ba86f57af9387eff5d8298cbef.png)
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5 . 已知双曲线
(
,
)的离心率为
,且经过点
.
(1)求
的方程;
(2)过原点
的直线与
交于
,
两点(异于点
),记直线
和直线
的斜率分别为
,
,证明:
的值为定值;
(3)过双曲线
上不同的两点
,
分别作双曲线
的切线,若两条切线相交于点
,且
,求
的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c5c2e64358e0ec7aa142c336d970306.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94440d3e4c073f94f2b266ff99d50e74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67ca5fd57c2c2fcc3c7a574fdd1467d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/31f8f7e40ba386c0a9675896b52752d6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e94f9d178764408489b0b336ea0ee42a.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
(2)过原点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/892909e49156f7dcc0650fcd65243877.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c8ffe24cf9f327aeb241225ab15ab1a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1456e81321ccb20077b34562ca9cffbc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/090b7ee52d644d0c630ef44aec1726dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a5702feefd657c2987d3fe5d9884f2d0.png)
(3)过双曲线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.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/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c796457a2c0d13a433fe5170e50948d2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc0874db73a250bdf664fbafaf78a81b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42eb873908c94e138e0d3c601860e4a2.png)
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解题方法
6 . 已知函数
(
)
(1)若曲线
在点
处的切线方程为
,求a的值;
(2)若对任意
,不等式
恒成立,求正整数a的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20c2b99a3fddd2cf8cf43bee3657e1a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22dd8b3dc4c609bab82d356a5cc2208d.png)
(1)若曲线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/942c2141d01bde6b48210c56a17fc75e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5828873f8369183faf71181cda5b61d2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ea05a2396e436b4df62d6328dbeaddc.png)
(2)若对任意
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4921923069c4f38a0af1ff8637e35b3c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94e26bbf4cc946214eb53eb269118082.png)
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7 . 如图,在四棱锥
中,平面
平面
,
是等边三角形,底面
是直角梯形,
,
,
.
为棱
的中点,求证:
平面
;
(2)求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93edc7bb513f40a89173121c8570cd65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55a675310c8ba418e5a59beb7317e21e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/080db3af81b29ed10144a1c2e2a4fb8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10df84d553a8826a7ce9bff4bf0d95b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c3753faebdc15d2d2e598d5ffc4487a6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6ae72f5e5891249caa10c43224da89c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a438393ddfc7da1804baf4932442bb35.png)
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8 . 从5名男生和3名女生中任选3人参加辩论比赛.
(1)求选出的3人中既有男生也有女生的概率;
(2)设随机变量X表示所选3人中女生的人数,求X的分布列和数学期望.
(1)求选出的3人中既有男生也有女生的概率;
(2)设随机变量X表示所选3人中女生的人数,求X的分布列和数学期望.
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9 . 已知数列
满足
,
.
(1)证明:数列
是递增数列;
(2)设数列
的前n项和为
,证明:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/039e4fe671d61e59b96ee525c9df43e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ba3f3c66384241b150a37ee61fad00f.png)
(1)证明:数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
(2)设数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41cf1da18d91f7c98086553d157d1a87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2d179459b5b54e72942d871cae7ed8b.png)
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10 . 在平面直角坐标系
中,利用公式
①(其中
,
,
,
为常数),将点
变换为点
的坐标,我们称该变换为线性变换,也称①为坐标变换公式,该变换公式①可由
,
,
,
组成的正方形数表
唯一确定,我们将
称为二阶矩阵,矩阵通常用大写英文字母
,
,…表示.
中,将点
绕原点
按逆时针旋转
角得到点
(到原点距离不变),求坐标变换公式及对应的二阶矩阵
;
(2)在平面直角坐标系
中,求双曲线
绕原点
按逆时针旋转
(到原点距离不变)得到的双曲线方程
;
(3)已知由(2)得到的双曲线
,上顶点为
,直线
与双曲线
的两支分别交于
,
两点(
在第一象限),与
轴交于点
.设直线
,
的倾斜角分别为
,
,求证:
为定值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ee31829d0d4d5f779a957d7df8058ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/956d57f34d39be3fe43b1bb28f8be623.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c02bc0c74292b1e8f395f90935d3174.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8701e0cce437edc830438b4fe6277d89.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0859290725efef72a1b04f473d07da6e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c02bc0c74292b1e8f395f90935d3174.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c84c4a85e9f31e35bc48c15d9873a03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c84c4a85e9f31e35bc48c15d9873a03.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/7ee31829d0d4d5f779a957d7df8058ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8701e0cce437edc830438b4fe6277d89.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0859290725efef72a1b04f473d07da6e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
(2)在平面直角坐标系
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ee31829d0d4d5f779a957d7df8058ab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/377a2333ff8c63cbdb20b882d6d5a7ec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15615de1a6df206dbd081251f676578e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
(3)已知由(2)得到的双曲线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.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/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7656f7488ae17565eded6173dbeb4837.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67d822262ff00915910e5b87d81ad1ba.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d97dc3b752832906de41447bb58a341.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b8dc4c63a548b91061528aa11058de75.png)
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