1 . (1)用分析法证明:
(当且仅当
时等号成立);
(2)设
为曼哈顿扩张距离,其中
为正整数.如
.若
对一切实数
恒成立.设
,且
,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c76da5edd4633d1fb68e3a4ede06473.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd68c14adb3cf12d8f77aec55a053284.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/350bc6680b01296d43c94b4d2477c1f1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a47a512e82abbcd0a647239620e8be39.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c70c57ebaf9a10ac167d32017564f027.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2684b72f9f38f5046c8ecd4280b7b14b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f916ad5246cc2f42386422d8726ecdfe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/485a2d99320384a0857b00ce9ab9e990.png)
您最近一年使用:0次
2 . 使用科学、正确的方法证明.
(1)已知
,试用分析法证明:
.
(2)已知
,
,求证
与
中至少有一个小于2.
(1)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b6c5526947e9bef051bc3bdf7fd186d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2b1411bbc505b5056e68e077d18e06b.png)
(2)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d0bd65eb59d0acde6f5955490696c6b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f9e131cdd242d56b6dba05ab3363ef3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10fe4e9871c2acac03e9a3388fd2877e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3a2b29b47d6c7753d5359883c105c68d.png)
您最近一年使用:0次
3 . (1)求证:
;
(2)已知
,
,且
,用反证法证明:
和
中至少有一个小于2.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94b3d03b6098d2f3f30d213d830d6a84.png)
(2)已知
![](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/69bbd0aae5a4f6129fc78f88f662f092.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5360e1dce424ae202f4ca4e5b842499f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/361751a03c628b8ddb0952a7390f7810.png)
您最近一年使用:0次
2021-10-13更新
|
281次组卷
|
4卷引用:陕西省西安市鄠邑区第一中学2021-2022学年高二下学期第一次月考文科数学试题(B卷)
4 . (1)证明:
;
(2)已知:
,
,且
,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/734f585f8cfc92522f6daf997ebec04d.png)
(2)已知:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08115d6d9f876dea921a4d32260ff1fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/061813f1ec633c5c4c393c4de7938322.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a945b19a5442a7edfa8d0f1d4ef488da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58b3eeae9616ea62a988bde7a82ddc98.png)
您最近一年使用:0次
2021-05-28更新
|
496次组卷
|
4卷引用:陕西省西安中学2021-2022学年高二上学期期末理科数学试题
5 . 不等式证明:
(1)证明不等式:
(其中
皆为正数)
(2)已知
,
,
,求证:
至少有一个小于2.
(1)证明不等式:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/75fbd934eef4b3b38cb981b60cc0af6e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b0fffbec1fe851795dfdd448bf0d165.png)
(2)已知
![](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/69bbd0aae5a4f6129fc78f88f662f092.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f3b7d1702786875b9984fe517fa1360.png)
您最近一年使用:0次
2020-03-19更新
|
833次组卷
|
3卷引用:陕西省西安中学2017-2018学年高二(实验班)下学期期中数学(理)试题
陕西省西安中学2017-2018学年高二(实验班)下学期期中数学(理)试题河南省南阳华龙高级中学2019-2020学年高二5月月考数学(文)试题(已下线)2.2.2 间接证明-2020-2021学年高二数学(理)课时同步练(人教A版选修2-2)
6 . 在△ABC中,角A,B,C的对边分别为a,b,c,已知a,b,c互不相等,且
.
(1)试比较
与
的大小;
(2)求证:B不可能是钝角.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cd5a7ec932f12eacb2e8793af166d33.png)
(1)试比较
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61fe34b1cc3a3cfcfad66fb03b9e22c1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c147d6cbd7cbaeb8ec08a0ba69cd59dd.png)
(2)求证:B不可能是钝角.
您最近一年使用:0次
解题方法
7 . 类比在数学中应用广泛,数与式、平面与空间、一元与多元、低次与高次、有限与无限之间有不少结论,都是先用类比猜想,而后加以证明得出的.在
中,
,
,
,则
外接圆的半径
,由此类比,在四面体
中,三条侧棱两两垂直,三条侧棱长分别是
,则该四面体外接球的半径为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7e3262fc038bbec5e7c8cc47df08bef7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e781a2489271bfd1597cba1bb6f5887.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df81cda12d7601d58b1d9c7c180c4d66.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/817d63b092387c04b941f113a014a70d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
A.![]() | B.![]() |
C.![]() | D.![]() |
您最近一年使用:0次
名校
解题方法
8 . 已知复数
满足
.
(1)求
的最小值与最大值;
(2)若z所对应的点在第一象限,且
为实数,求证:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78b78b8fe7da9e76822d85a2a0336484.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64ec00601d3297c94a1a224421df7d1d.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48c344fd5607cb7a3ce319165fbf45f8.png)
(2)若z所对应的点在第一象限,且
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/59ae50806d8c14f0275864b30e9f30a7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86fa4b7b50a233a09e7da199f75bc9dc.png)
您最近一年使用:0次
2023-05-10更新
|
171次组卷
|
2卷引用:陕西省西安市鄠邑区2022-2023学年高二下学期期中文科数学试题
9 . 用反证法证明命题:“三角形的内角中至少有一个大于
”时,反设正确的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d5bca00fa20e6e80480b9d06d2e52ee.png)
A.假设三个内角都不大于![]() | B.假设三个内角都大于![]() |
C.假设三个内角至多有一个大于![]() | D.假设三个内角至多有两个大于![]() |
您最近一年使用:0次
10 . (1)已知
为正数,
,
,用反证法证明:a,b中至少有一个不小于6;
(2)用分析法证明:当
时,
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b9cf5913674be8a7410df303a518062.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1cbacc1c7dbb5c5e40d1dea67959c93a.png)
(2)用分析法证明:当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0935b0d5568370418871fa7a6c47162d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be005ace3e23bdac0e3549c2b5543880.png)
您最近一年使用:0次
2023-05-10更新
|
76次组卷
|
4卷引用:陕西省西安市鄠邑区2022-2023学年高二下学期期中文科数学试题