名校
解题方法
1 . 对于定义域为R的函数
,如果存在常数T,
,使得
是以T为周期的函数,则称函数
为正弦周期函数,且称常数T为
的正弦周期.
已知函数
满足以下四个条件:
①函数
是以T为正弦周期的正弦周期函数;
②函数
的值域为R;
③函数
在区间
上单调递增:
④
,![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294bab9bbfb414f2d1fb0844aee4fc9e.png)
(1)分别判断函数
、
是否为正弦周期函数.如果是正弦周期函数,写出它的正弦周期,(不需证明).
(2)设
,求证:对任意
,存在唯一的
使得
.
(3)求证:对于任意的
,都有
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d8b6894e8c345a035e89ec672503a01f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7eecacbdc5c2a7e7ac00daea8c448098.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16a0ab6eeb2b475795eae6f432789105.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d8b6894e8c345a035e89ec672503a01f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d8b6894e8c345a035e89ec672503a01f.png)
已知函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93e03ad0c315806342d6cd732a0b91a3.png)
①函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93e03ad0c315806342d6cd732a0b91a3.png)
②函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93e03ad0c315806342d6cd732a0b91a3.png)
③函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93e03ad0c315806342d6cd732a0b91a3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aaafa094244d569dd54bd8036c7f0b6d.png)
④
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93941e7f4bea588b5020035760ba0e05.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294bab9bbfb414f2d1fb0844aee4fc9e.png)
(1)分别判断函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f19e893159870d911d83af4f4b2b70ea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6978ab291c9908f871c1178a2dea35a9.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6a46e678bf9d2df5ad4c782b3dc22f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/761e8a1b81490a2db7aa84f2104cb3fc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea34ffa60956e957a07faf386e43a20c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b0b836129720c860faf76f2703b61016.png)
(3)求证:对于任意的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f7999305fcdf5fd209920cc42cfe6f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aab11dce5b8ee5cbe5f1439c1b9e4dc3.png)
您最近一年使用:0次
2 . 已知:底与腰之比为
的等腰三角形为黄金三角形.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/23/d906e69c-33ad-47c1-87a1-046eb54ce27b.png?resizew=337)
(1)如图1,
即为黄金三角形尺规作图.已知
,求
长为______,
为______.
(2)如图2,即为正五边形尺规作图.求证:五边形
(所作图形)即为正五边形.
(3)请用另一种方法尺规作图作出正五边形.简要叙述作图方法,无需作图.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/029d393bb07b7140905b85f550519de4.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/23/d906e69c-33ad-47c1-87a1-046eb54ce27b.png?resizew=337)
(1)如图1,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d39b8d91afc34e4a9b0fdbb6bafb9087.png)
(2)如图2,即为正五边形尺规作图.求证:五边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9142a8490de14a87eda628ffa7e28982.png)
(3)请用另一种方法尺规作图作出正五边形.简要叙述作图方法,无需作图.
您最近一年使用:0次
3 . 设
为实数,定义
生成数列
和其特征数列
如下:
(i)
;
(ii)
,其中
.
(1)直接写出
生成数列的前4项;
(2)判断以下三个命题的真假并说明理由;
①对任意实数
,都有
;
②对任意实数
,都有
;
③存在自然数
和正整数
,对任意自然数
,有
,其中
为常数.
(3)从一个无穷数列中抽出无穷多项,依原来的顺序组成一个新的无穷数列,若新数列是递增数列,则称之为原数列的一个无穷递增子列.求证:对任意正实数
生成数列
存在无穷递增子列.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/796bb39a2ab23cfdb6e463ab30a7af2e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4758b555ca9b157cc074f1e4a092e34a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f61c0bb2370087736c8e00e108b48c8.png)
(i)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20c051dc675bcca6a8f70a3dbe922354.png)
(ii)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3121951a9b059eef49b4a346d3aa2b94.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c400b893304c51631873ded41027cf48.png)
(1)直接写出
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4e0c84de10f0f2186313169c3dc997b.png)
(2)判断以下三个命题的真假并说明理由;
①对任意实数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81fbdf49cd00af1ff87259836ddd9f6b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/508cd31480a898a71472e2d5d22377c7.png)
②对任意实数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81fbdf49cd00af1ff87259836ddd9f6b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19c99515d9952f2f7739fd750a31128f.png)
③存在自然数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a178f2c27906fc74afee1b7d7d52746.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1563da7b0f046a469476668a3686e8f9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f59a60eb4d63ebc879ae5c26413bcdcc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
(3)从一个无穷数列中抽出无穷多项,依原来的顺序组成一个新的无穷数列,若新数列是递增数列,则称之为原数列的一个无穷递增子列.求证:对任意正实数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da069077c220af26b9e77b02baeee4a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4758b555ca9b157cc074f1e4a092e34a.png)
您最近一年使用:0次
4 . 对于空间向量
,定义
,其中
表示
这三个数的最大值.
(1)已知
,
.
①写出
,写出
(用含
的式子表示);
②当
,写出
的最小值及此时x的值;
(2)设
,
,求证:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aeaf03753884e4d0cf43c000e55eee6f.png)
(3)在空间直角坐标系O−xyz中,
,
,
,点P是以O为球心,1为半径的球面上的动点,点Q是△ABC内部的动点,直接写出
的最小值及相应的点P的坐标.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bcca7d5f22aa5c008bd7f6a5be2e0e9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09abcc323c73834a7a96104fb887afc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a4461408813c1476a8a8073c83b8989.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a14c388e1e2e5a2ff1ccf6caffbee0d.png)
(1)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79726ab35566fedc08d41264e26d6633.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20538dc38f7c098245d9d21e890167f3.png)
①写出
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/29fc07cec37c06a773869d32fbb36da3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e21d2dc706c9e83e5719f3d286c03cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
②当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53168695826b0a33a23067b76173c7e5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3b02bd3d97f303b6c23ad4b26d93f83.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3619a3f526eca4e29fd3edc6bd485f61.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8383f8f4d22147a863c687f7c99798d0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aeaf03753884e4d0cf43c000e55eee6f.png)
(3)在空间直角坐标系O−xyz中,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d9fd85dc30357d4b88af5a852a8ce05.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/caa8d7d26716e375a963fb0b202595d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cf516af881074dfc62c198f6715c411.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6408aad25068e98985c9df8c1cc74661.png)
您最近一年使用:0次
2022-11-02更新
|
523次组卷
|
6卷引用:北京市北京师范大学附属实验中学2022-2023学年高二上学期期中考试数学试题
2022高一·全国·专题练习
5 . 材料一:如果一个三位正整数满足十位数字大于个位数字,且十位数字与个位数字之和等于百位数字,那么称这个数为“下降数”.例如:
,满足
,且
,所以
是“下降数”;
,满足
,但
,所以
不是“下降数”.
材料二:对于一个“下降数”
(
,
,
,且
,
,
为整数),交换其百位和十位得到
,规定
,例如:321是“下降数”,
,
.
(1)判断:743 “下降数”,523 “下降数”(填“是”或“不是”);
(2)设m为任意一个“下降数”,求证:
能被11整除;
(3)若
,
都是“下降数”,其中
,
(
,
,
,
,且
,
,
,
均为整数),若
=117,求满足条件的
和
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8cb3a3a191e6852428d56fc1f484dac8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad6446d840ed9f208a98f59fec9f7630.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fdc114012e9d5888ca8ac6b6eacd306e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b3e22a3ff259172de8c9411405650f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cabbadab93c4c9a909482e52d8d2de16.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/523a449a62805b21e5ef6769b93124eb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a352a9a6e0a6e3ac462f0004ba05125f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2abe6ccdbf4e5000d471b493f5982d98.png)
材料二:对于一个“下降数”
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0a66194bf888fe60458a2e32a98710a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c40654a0135a2713cfe30a53445cbe7c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3c035b9c9a3ef570ba56fd4da127702.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/d1c526241f17d718dbe18df1e1a796a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef07608cb0afaaaa571679e6ba4e8ccc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/688d06c7524da82f8ed91606869649dc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e629a01f4f8adb0edee9d05a2ac61c1.png)
(1)判断:743 “下降数”,523 “下降数”(填“是”或“不是”);
(2)设m为任意一个“下降数”,求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5bb215f28e5eea7ff4c7ca5ee9e2216.png)
(3)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5873c01192b7d33b7483f444f90b5b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ced7c9886816c7cbaa48a29248d2013d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b7b8350613bfaf2c964cc2905bde21b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b38801a4ec7a47cfd6cea29f742248b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/815f1cce3f13169fb82a377c61e3e545.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.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/a900aeb7d696bc3af5b92dacd87bd729.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5873c01192b7d33b7483f444f90b5b0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36a1b09c653185842513e24ebba60bb3.png)
您最近一年使用:0次
6 . 类比于平面三角形中的余弦定理,我们得到三维空间中的三面角余弦定理;如图1,由射线PA、PB、PC构成的三面角
,
,
,
,二面角
的大小为
,则
.
,平面
平面ABCD,
,
,求
的余弦值;
(2)当
、
时,证明以上三面角余弦定理;
(3)如图3,斜三棱柱
中侧面
,
,
的面积分别为
,
,
,各侧面所应得平面与底面所成的三个二面角分别记为
,
,
,请用文字和符号语言描述你能够得到的正弦定理在三维空间中推广的结论,并证明.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa26fadeee2becc192fa53d778445d52.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eac229a5e782559ffb0f271cbfc01c6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef6ab2d197160f40b72fe0abb3fe527d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a438393ddfc7da1804baf4932442bb35.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3e14113e0a7ac6b8e1faf51dbcc6dbd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0671b4776e142e17a79af5b3f0378ef7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7e3c9e7c05de9838c0c5d762720d3ef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f81e24376a13d648c2ed0dc73bc710e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/947c03e48c4be7485f1547817f890c53.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/17cc100e36303b3566d91e4756594cf2.png)
(3)如图3,斜三棱柱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e168672b47d7e64dc1b404f8882c7dcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d9a8181f7a7fe7f3fac872ce9534f15.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e097c8d4c948de063796bd19f85b3a9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e0bd63f55069a3bc870915010b39225.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6899bf9cadae2ccdb14cbc87d4f280ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/25f64fa38725c136504f723019a18dc5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e93fa313adc4ac7608ba9449fd755212.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e8d4017e1a37acb0c8e00508be472b2.png)
您最近一年使用:0次
2022-12-25更新
|
570次组卷
|
4卷引用:上海市嘉定区第一中学2022-2023学年高二上学期12月月考数学试题
上海市嘉定区第一中学2022-2023学年高二上学期12月月考数学试题(已下线)第五篇 向量与几何 专题17 三正弦定理、三余弦定理 微点2 三正弦定理、三余弦定理综合训练(已下线)第二章 立体几何中的计算 专题一 空间角 微点13 三正弦定理与三余弦定理综合训练【培优版】广东省深圳市深圳大学附属中学、龙城高级中学第二次段考2023-2024学年高一下学期5月月考数学试题
名校
解题方法
7 . 对于无穷数列
,若对任意
,且
,存在
,使得
成立,则称
为“
数列”.
(1)若数列
的通项公式为
的通项公式为
,分别判断
是否为“
数列”,并说明理由;
(2)已知数列
为等差数列,
①若
是“
数列,
,且
,求
所有可能的取值;
②若对任意
,存在
,使得
成立,求证:数列
为“
数列”.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ef6d44448092ebdb9e4a49d866a749.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b513ec2b07b56d03eae65c3680c26b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7d9712c3b25f3030e166e136d3a4686.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83a6bc55d5eb2c3d085b62ffcd8d138d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/efed6061ac46ad56f61e596e88e8d869.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/57ef6d44448092ebdb9e4a49d866a749.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
(1)若数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86433d7ac6373f71563fe6f253bc6cda.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb5754c6ce45757c909db734f52912da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c80cac70a523e0f3a7429957cb69b50f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
(2)已知数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
①若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f50efab51e1985b1f1298345cdef6bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/642a443e3315a7fb6489b01fad7e3215.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e88093a749c0d46e0ee931ecfaff925.png)
②若对任意
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af5cf9c12181dd8683944b2b30bf8e08.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83a6bc55d5eb2c3d085b62ffcd8d138d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/110311b55d3b8073e0da21096fa91f4d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
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2022-12-04更新
|
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|
5卷引用:北京市十一学校2023届高三上学期12月月考数学试题
北京市十一学校2023届高三上学期12月月考数学试题北京市十一学校2023届高三上学期11月月考数学试题(已下线)北京市西城区2022届高三二模数学试题变式题16-21北京市朝阳区第八十中学2022-2023学年高二下学期期中考试数学试题(已下线)2023年北京高考数学真题变式题16-21
名校
解题方法
8 . 在解决问题:“证明数集
没有最小数”时可用反证法证明:
假设
是
中的最小数,则存在
,
可得:
,与假设中“a是A中的最小数”矛盾,
所以数集
没有最小数.
那么对于问题:“证明数集![](https://staticzujuan.xkw.com/quesimg/Upload/formula/148c4902eb8e6a73046dedab761e3abf.png)
,并且
没有最大数”,也可以用反证法证明:我们可以假设
是
中的最大数,则存在
,且
,其中
的一个值可以是__________ (用
、
表示),由此可知,与假设
是
中的最大数矛盾.所以数集
没有最大数.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79950aacd93566f38d8e16021d2eb23b.png)
假设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/abc7dff3ffdad01a473cc8bdb236f2d9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0914b68f106a912420705b2f3928ca42.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a2710435ef4f66f24a0f4b67d7e83f0e.png)
可得:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54bfb810e811cb3d9482e2ec0d8db742.png)
所以数集
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79950aacd93566f38d8e16021d2eb23b.png)
那么对于问题:“证明数集
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/148c4902eb8e6a73046dedab761e3abf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eb45566dd4ac7dd3524acdb890c29bb6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f313d192b9d871f1e543f8ac1209b0a9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ad6060180ef1fa5784a087be85d1f91.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1da9dcf6c319174c9ea2b1ceaed1649a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11a25178d007036b7fbde4ab793c98c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4cfc6ee6f3b4da7817d30e1b9dc36d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bff1301d5d66379471b648952aea6310.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/26e93d8fb77f5bd2c0fc690752dfd771.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d7e9f86738335a22298559db41037a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ad6060180ef1fa5784a087be85d1f91.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1da9dcf6c319174c9ea2b1ceaed1649a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1da9dcf6c319174c9ea2b1ceaed1649a.png)
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2022-10-26更新
|
181次组卷
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2卷引用:上海市进才中学2022-2023学年高一上学期10月月考数学试题
9 . 小明在学习“用函数的观点求解方程与不等式”时,灵光一动,为课本上一道习题“已知
为正数,求证:
.”得到以下解法:
构造函数
,
因为
,当且仅当
时取等号;
所以对于函数
可得
,当且仅当
时
,
即
,当且仅当
时可取等号.
阅读上述材料,解决下列两个问题:
(1)若实数
不全相等,请判断代数式“
”的取值是正还是负;(直接写出答案,无需理由)
(2)求证:
,并指出等号成立的条件.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/632244ea6931507f8656e1cc3437d392.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86546d8c56d9c72822cc2c834e240ad1.png)
构造函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/47b8cec10d676573f64f4c41cef66c5b.png)
因为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f566a7929ed7e6698b37254dde13361.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3df141b225e05cf3668952a97e78543c.png)
所以对于函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/47b8cec10d676573f64f4c41cef66c5b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a2932ebfce691f2ad62c3f1e82cbfebe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b12276c1c817ca996dd2f16b937d889b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c2b0eb6b8e515c616b5cdd4c37fefc3.png)
即
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86546d8c56d9c72822cc2c834e240ad1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f22fec5a381ae8aca93d876e54c79de.png)
阅读上述材料,解决下列两个问题:
(1)若实数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/077d221630f239441cbb334f10c8bca4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf6363a4d739742c94ac5a02425c9486.png)
(2)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a1baf5405b108ea80d74e6286b5200ce.png)
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名校
解题方法
10 . 设集合A的元素都是正整数,满足如下条件:①A的元素个数不小于3;②若
,则
的所有因数都属于A;③若
,
,
,则
,请回答下面的问题:
(1)证明:1,2,3,4,5都是集合A的元素
(2)判断2021是否集合A的元素,并说明理由
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3cc020b0997a2f37b214718112b79d8e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3cc020b0997a2f37b214718112b79d8e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eb9df3a17aa370eba2add2c13cfc2619.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63478e7cf55bad51bbd4ce1e23363e75.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3bad767600de4c7c7d2fa23bd2c2813f.png)
(1)证明:1,2,3,4,5都是集合A的元素
(2)判断2021是否集合A的元素,并说明理由
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