名校
1 . 根据多元微分求条件极值理论,要求二元函数
在约束条件
的可能极值点,首先构造出一个拉格朗日辅助函数
,其中
为拉格朗日系数.分别对
中的
部分求导,并使之为0,得到三个方程组,如下:
,解此方程组,得出解
,就是二元函数
在约束条件
的可能极值点.
的值代入到
中即为极值.
补充说明:【例】求函数
关于变量
的导数.即:将变量
当做常数,即:
,下标加上
,代表对自变量x进行求导.即拉格朗日乘数法方程组之中的
表示分别对
进行求导.
(1)求函数
关于变量
的导数并求当
处的导数值.
(2)利用拉格朗日乘数法求:设实数
满足
,求
的最大值.
(3)①若
为实数,且
,证明:
.
②设
,求
的最小值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4a1d0dba29a77dd111efcde543d6c1f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc4c14935585e8fa61d032730867d771.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67b6f154c6b2de5695eb1807b98c2c63.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df64046e91b047037f19e4032e3b6de3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/809615d1f91508e2c6c0cda7e592c479.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/244021f826099b18e31af1143597bba2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eb5be11a5e6aaf00b2833930b198b4cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0203b006524305c3d8ee0b6c34cd872b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4a1d0dba29a77dd111efcde543d6c1f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc4c14935585e8fa61d032730867d771.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b0fffbec1fe851795dfdd448bf0d165.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f1c3c1ed4fb65ab9505ad8078d8d0fb5.png)
补充说明:【例】求函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d7ca0caa9933b7afd4bed2683140a07.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/aebdee8d81b048b5aa520f7e8ba56ff2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a1e15a54c6122c695239107dd0901bc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/244021f826099b18e31af1143597bba2.png)
(1)求函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b3d9ab2fcf15b94f33cb64f84ed906c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d053b14c8588eee2acbbe44fc37a6886.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b384412acba251d87902ab928902f16.png)
(2)利用拉格朗日乘数法求:设实数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b0fffbec1fe851795dfdd448bf0d165.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c45d8122b61de13875003d00c002c5b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de725a9fc66f67abbe0015131846a648.png)
(3)①若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a14c388e1e2e5a2ff1ccf6caffbee0d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd24c686fbaaa68705d654b880481ffe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e778f95c72fec00bfbbc63e6dfd0c460.png)
②设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/497d269c30eec393e3f0e877ddbe2983.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ade042c085bbad8aeaf111b9f4c33408.png)
您最近一年使用:0次
名校
2 . 已知函数
,
.
(1)解方程![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f9708c59f51c8ed59a859e288e9ac024.png)
(2)当
时,有
最大值为1,求实数
的值;
(3)若方程
在
上有4个实数解,求实数
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1697647bba92906e733fb696f622a2e2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4139cddc2af2ef0900496dce24274d2.png)
(1)解方程
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f9708c59f51c8ed59a859e288e9ac024.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1591d4244dcf5539a4ae98f554e91e61.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4669810732b633b60dbeaf0bf57204f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
(3)若方程
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f955a011428f5e0d962cd57f8e73b396.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d188ec2580e273ce87e51653a2177ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
您最近一年使用:0次
名校
3 . 已知函数
.
(1)当
时,解不等式
;
(2)若关于
的方程
在区间
上恰有一个实数解,求
的取值范围;
(3)设
,若存在
使得函数
在区间
上的最大值和最小值的差不超过1,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ab5c53352f3eafd25b5dbf4ee5bbbd6.png)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e65397f11ea8af736f38debadf420c4a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/018857ec6e498113b3b12a730d9313da.png)
(2)若关于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f198f304b60422fb5065dcc742ab48a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc6554ac3dff4a59833e407db887f6e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
(3)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94440d3e4c073f94f2b266ff99d50e74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6555c4166361c548b6f4f692d9a66cb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fe7d5809da02c15a43a0e9a898b9086.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c93c82944db4a310a2047dd6d8966162.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
您最近一年使用:0次
2020-02-28更新
|
695次组卷
|
4卷引用:上海市曹杨二中2019-2020学年高一上学期期末数学试题
4 . 已知函数
.
(1)设
是
的反函数.当
时,解不等式
;
(2)若关于
的方程
的解集中恰好有一个元素,求实数
的值;
(3)设
,若对任意
,函数
在区间
上的最大值与最小值的差不超过
,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e8e4900f308f9aba73d06964d8e61f54.png)
(1)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ab05c7c140f76ce8618a6694b57b30e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d8b6894e8c345a035e89ec672503a01f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b550ee821ee1838384835e81fc34b67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6bd20834857c93040879c02070035b6.png)
(2)若关于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8b542881ccda4af9d4cbc1df4ead2638.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
(3)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94440d3e4c073f94f2b266ff99d50e74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb848c2e3353bcb126d14fed803fe2a5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d8b6894e8c345a035e89ec672503a01f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aaca9c1dac608a386df1848e8459ce9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e24d42f61784c642e9eb1316afdd2ad.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
您最近一年使用:0次
2020-02-01更新
|
270次组卷
|
2卷引用:上海市杨浦区2018届高三上学期期中数学试题
名校
5 . 已知函数
.
(1)当
时,解不等式
;
(2)若
时,
恒成立,求
的取值范围;
(3)关于
的方程
在区间
内恰有一解,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ba3ad818f68e43620ef8abfcf388f55.png)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/302337058242c7b78e3eb4ac7210b7ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f234b18b78bdfbeec2860a3f95a0be84.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0bb71d0371fd8c9ff7d7ae95c4da20fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ef854983f312d4765a6fa91bc78974cc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
(3)关于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee07d18565c599ffbdef959e95e9ec68.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d0d025548b510173aeeea5e02d39d0d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
您最近一年使用:0次
2019-11-30更新
|
1044次组卷
|
4卷引用:辽宁省大连市育明高级中学2019-2020学年高一上学期期中数学试题
名校
6 . 已知
,函数
.
(Ⅰ)当
时,解不等式
;
(Ⅱ)若关于
的方程
的解集中恰有一个元素,求
的取值范围;
(Ⅲ)设
,若对任意
,函数
在区间
上的最大值与最小值的和不大于
,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/44aca6c00903b9dd306287ba3bb91035.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b3d79b174269eb75464c8f51ea5bbda0.png)
(Ⅰ)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b550ee821ee1838384835e81fc34b67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98ec7ef12927ef4e2d8f6721a0ae6b15.png)
(Ⅱ)若关于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f19f45b84efe779093d998513130043e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
(Ⅲ)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94440d3e4c073f94f2b266ff99d50e74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64b412654a4e5b9d64e2bfb6f5b12ce7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d8b6894e8c345a035e89ec672503a01f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97c2e5f67f3eee8766347d429b3de437.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c9bf7f9244224fd181cbc0594de34f8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
您最近一年使用:0次
2018-01-26更新
|
1931次组卷
|
2卷引用:天津市新四区示范校2017-2018学年高一上学期期末联考数学试题
名校
解题方法
7 . 一般地,我们把函数
称为多项式函数,其中系数
,
,…,
.设
,
为两个多项式函数,且对所有的实数
等式
恒成立.
(1)若
,
.
①求
的表达式;
②解不等式
.
(2)若方程
无实数根,证明方程
也无实数解.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5bf5ba3261da10ef4c78b5d611aaf60.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f35f7dcce39f3d4dc6b7faf84dc1d0a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e72adb45c60c2f63b46e65ff787302bf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96a5d7258973bf6c6afab73fcc1e8263.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fe7d5809da02c15a43a0e9a898b9086.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be1ce3f01e2b6364f9a9fdaf197d5e29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34c3e5078eacd04040a3b843f2f8a894.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df4ab5ed446cb4d85ee8f9e93e0985e8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eb4935611969e644511329f6b0dbbf3b.png)
①求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be1ce3f01e2b6364f9a9fdaf197d5e29.png)
②解不等式
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca77cbddad9b9b82ee918612de679f27.png)
(2)若方程
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f8bfb563f79688d136e0cb958b5153c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86ed16a1c5b976b543af7d418a9e4905.png)
您最近一年使用:0次
2017-10-31更新
|
454次组卷
|
3卷引用:北京西城35中2016-2017学年高一上学期期中数学试题
8 . 已知
,函数
.
(1)当
时,解不等式
;
(2)若函数
为奇函数,试求
的值;
(3)若关于
的方程
的解集中恰好有一个元素,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22dd8b3dc4c609bab82d356a5cc2208d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e02113fb34201302c2c68f71b6efdc3.png)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b550ee821ee1838384835e81fc34b67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6c2e0bb6d63b7bcaee92a470d58cc399.png)
(2)若函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fffac67cbe37813c942198f7ffae609.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
(3)若关于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c29b694e039a36d73a89ea94edf57091.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
您最近一年使用:0次
2017-10-11更新
|
1476次组卷
|
3卷引用:江苏省镇江市高三10月月考数学文科试题
解题方法
9 . 已知函数![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6db168f7ee71b08f65d33d06f65d3bf0.png)
(1)当
时,解关于
的不等式
;
(2)当
时,解关于
的不等式
;
(3)不等式
对任意
恒成立,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6db168f7ee71b08f65d33d06f65d3bf0.png)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b550ee821ee1838384835e81fc34b67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f638c4a23354b0ef4b83e52e16b0ffd.png)
(2)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/10bbdef421c976962a270a2beabbad91.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f638c4a23354b0ef4b83e52e16b0ffd.png)
(3)不等式
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1aef39b219840117b39dbd0e4cb75d5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58df0c7adbd7f2a101e51deb7105035c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
您最近一年使用:0次
名校
解题方法
10 . 定义在R上的函数
满足:对于
,
,
成立;当
时,
恒成立.
(1)求
的值;
(2)判断并证明
的单调性;
(3)当
时,解关于x的不等式
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/df6593a700bf3e89107556454666b787.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/95cccdff49c3efe6e7a7dbbf69db9319.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab0c6f119137e1b6760d55956d99d963.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e541ea2f855f981c96207070683d388.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c73a98c1b3504e09bfbe0db849b0d24.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3e38fffbc7ab9882480f4faa72390e23.png)
(2)判断并证明
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
(3)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94440d3e4c073f94f2b266ff99d50e74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc94e973ff01962e8d5a1807e9ccff23.png)
您最近一年使用:0次
2023-08-06更新
|
1638次组卷
|
12卷引用:四川省攀枝花市第三高级中学2022-2023学年高一上学期第一次月考数学试题
四川省攀枝花市第三高级中学2022-2023学年高一上学期第一次月考数学试题云南省下关第一中学2023-2024学年高二上学期见面考试数学试题(已下线)高一上学期期中复习【第三章 函数的概念与性质】十大题型归纳(拔尖篇)-举一反三系列(已下线)专题02 高一上期中真题精选-期中考点大串讲(人教A版2019必修第一册)辽宁省大连长兴岛高级中学2023-2024学年高三上学期第一次月考数学试题四川省资阳市乐至县乐至中学2023-2024学年高一上学期10月月考数学试题河南省郑州市中牟县第一高级中学2023-2024学年高一上学期10月月考数学试题安徽省安庆市桐城中学2023-2024学年高一上学期第二次教学质量检测数学试题福建省莆田市第九中学2023-2024学年高一上学期期中检测数学试题(已下线)第三章 函数的概念与性质【单元基础卷】-【满分全攻略】(人教A版2019必修第一册)山东省日照市第一中学2023-2024学年高一上学期12月月考数学试卷广东省广州市第六中学2023-2024学年高一上学期期中考试数学试题