21-22高一·湖南·课后作业
解题方法
1 . 如图,正方形ABCD与正方形ABEF所在平面相交于AB,在对角线AE,BD上各有一点P,Q,且AP=DQ.求证:
平面BCE.(用两种方法证明)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b1a378a3a4660eb1ece52085a9b44d5.png)
![](https://img.xkw.com/dksih/QBM/2022/2/19/2920038491275264/2922039224254464/STEM/d0978593-d49d-4eec-a047-34cc1d692a9f.png?resizew=155)
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2 . 下列各题在应用数学归纳法证明的过程中,有没有错误?如果有错误,错在哪里?
(1)求证:当
时,
.
证明:假设当
时,等式成立,即
.
则当
时,左边
=右边.
所以当
时,等式也成立.
由此得出,对任何
,等式
都成立.
(2)用数学归纳法证明等差数列的前n项和公式是
.
证明,①当
时,左边=
,右边
,等式成立.
②假设当
时,等式成立,即
.则当
时,
,
.
上面两式相加并除以2,可得
,
即当
时,等式也成立.
由①②可知,等差数列的前n项和公式是
(1)求证:当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1933b7c3ace69622339353431c519b13.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f57a93680033e45aa7f4226edcdd0d0c.png)
证明:假设当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/769becde4d8d0c1b487c727bd562bb1f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0025cda4a1182a9341e28cf021b3d963.png)
则当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63ba21f3d0cfc86d40e2e06446623ce0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7f6974560f10fa3047f2f6bf77bc1ed.png)
所以当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63ba21f3d0cfc86d40e2e06446623ce0.png)
由此得出,对任何
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1933b7c3ace69622339353431c519b13.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f57a93680033e45aa7f4226edcdd0d0c.png)
(2)用数学归纳法证明等差数列的前n项和公式是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba269108f5612e25822bce40eab39a59.png)
证明,①当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c87b351f16728b0023fd63678f8103c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5202cc8a5f8259b25ba31346feafcfe1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c4704eff3c92eaa4e6b040c4bbb542b.png)
②假设当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/769becde4d8d0c1b487c727bd562bb1f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0915a8cffc2076e75fdda3484e3f5a6a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63ba21f3d0cfc86d40e2e06446623ce0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d19930a09d20a1b2497702a0d2211183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de1ca469cabd255b7fbe8179ae8f6630.png)
上面两式相加并除以2,可得
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bff62fdb872da6debad99b36880d61a6.png)
即当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63ba21f3d0cfc86d40e2e06446623ce0.png)
由①②可知,等差数列的前n项和公式是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba269108f5612e25822bce40eab39a59.png)
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2021-02-07更新
|
590次组卷
|
5卷引用:人教A版(2019) 选择性必修第二册 新高考名师导学 第四章 4.4 数学归纳法
3 . 分析法又称执果索因法.若用分析法证明“设
,且
,求证:
”索的因应是______ .
①
;②
;③
;④
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce613eaa5df46a50174085ef5d1087fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e56f4504e0f80fd031c8b5f41832e03.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bff6d61a8eaff20b364a9e3235577c69.png)
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/481ee0d1e39e92a4732eea90225eb94c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6e90787c63ca5b5f1a45e0f6e85aaa1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d8062c16e427bcf70b7ab5c94e8f25a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e40e5c797b097deb1f9e89bcb3a405f1.png)
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4 . 已知函数
.
(1)判断函数
的奇偶性,并证明;
(2)求证:
在
上为增函数.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7652ff7e0aed153658c0279dffd5b86e.png)
(1)判断函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d27e0400d730672ae2110ff48786dd1d.png)
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5 . 设函数
对任意的实数
、
都有
,且当
时,
.
(1)在你学过的函数中,有没有满足上述条件的函数?若有,试举一例;
(2)试探求
的值,并写出过程;
(3)求证:当
时,
;
(4)试猜想
的单调性,并证明你的结论.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be114c655f251cc3fdccae5d4c520985.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ac82501b461d044f78e7ae5b86cd3c3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08115d6d9f876dea921a4d32260ff1fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5456d544e2f8d22c08f3ccee002dad4a.png)
(1)在你学过的函数中,有没有满足上述条件的函数?若有,试举一例;
(2)试探求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f54b6a060d6c51a328341df76013bd89.png)
(3)求证:当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e541ea2f855f981c96207070683d388.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5be1d8c6384d7fabddb693b2b7fcdf4a.png)
(4)试猜想
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fe7d5809da02c15a43a0e9a898b9086.png)
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名校
6 . 已知
,求证
的两根的绝对值都小于1,用反证法证明可假设__________
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7b8cfed3e48c308e325045cb87d7bdbb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1146110d4382c714c10de00dd1273b7f.png)
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7 . 已知函数f(x)=
,其中c为常数,且函数f(x)的图象过原点.
(1)求c的值,并求证:f(
)+f(x)=1;
(2)判断函数f(x)在(-1,+∞)上的单调性,并证明.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/802f4adf7c33387219bf1cf370aca9db.png)
(1)求c的值,并求证:f(
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95fcfaf750395f9e5b843f017aab25d9.png)
(2)判断函数f(x)在(-1,+∞)上的单调性,并证明.
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8 . 分析法又叫执果索因法,若使用分析法证明:“已知a>b>0,求证:
-
<
.”最终的索因应是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d012d124f04963fb72a68af40d5f8f42.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c462d08d75fcc7ccf9c3ecea1972e26.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9c632c082ad3e3fd8389b26d0875559.png)
A.![]() | B.![]() | C.1<![]() | D.a-b>0 |
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2019-05-19更新
|
241次组卷
|
2卷引用:吉林省蛟河市第一中学校2018-2019高二下学期期中考试数学(理)试题
名校
解题方法
9 . 已知函数
的图象经过
,
两点.
(1)求
的解析式;
(2)判断
在
上的单调性,并用定义法加以证明.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6bc7179a01c937e7a4f3281093bb9d6b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b69abe959988e4c8c0739f5857ccfb0f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcf57804a00d72521b08f36a3034f83d.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
(2)判断
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7242b2ab643f9470da77e29d043b893.png)
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名校
解题方法
10 . 如图,在底面为菱形的直四棱柱
中,
,
分别是
的中点.
;
(2)求平面
与平面
所成夹角的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/709a9e8bdb91467826fdf8ee31ac63c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b199a99e53d67ff4abf233930961a29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4cf79ee8726310da8faf61f70cfa682.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78fe6d64ca3dd8568a059d4b867d00ca.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a8035fc825a001d7d9a3dacd8271662.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
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2024-03-12更新
|
1324次组卷
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5卷引用:山东省泰安市2024届高三下学期一轮检测数学试题
山东省泰安市2024届高三下学期一轮检测数学试题上海市宜川中学2024届高三下学期2月开学考试数学试题湖北省天门市天门中学2023-2024学年高二下学期3月月考数学试题(已下线)信息必刷卷04(上海专用)(已下线)专题03 空间向量及其应用全章复习攻略--高二期末考点大串讲(沪教版2020选修)