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
解题方法
2 . 已知函数
.
(1)计算
的值;
(2)解关于
的不等式:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2cd706da48b6021cccd94788724999c1.png)
(1)计算
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fc39a2b9af193e28979d48c4b952208b.png)
(2)解关于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/542610eef9407c6ec6beee8aa97d77bd.png)
您最近一年使用:0次
3 . 已知函数![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e28c7ab2bfaf8e31633d19d5929e98c.png)
(1)解不等式
;
(2)若关于
的方程
在
上有两解,求
的取值范围:
(3)若函数
,其中
为奇函数,
为偶函数,若不等式
对任意
恒成立,求实数
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0e28c7ab2bfaf8e31633d19d5929e98c.png)
(1)解不等式
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c518b3d58a796d8a5456b4dd73b46380.png)
(2)若关于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5a92ad96177b893b2f2060fd6b1bf8f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be309ee083e0060769afa2a7062125fd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
(3)若函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bc50f609440a36953561a88e8acfee1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4669810732b633b60dbeaf0bf57204f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a813b5adbf5c7082561237894ba6d599.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eff55088f345dd9d3dd241d3bf3e2da8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ee49aedadda4e9494e7034ec55c7ebd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
您最近一年使用:0次
名校
解题方法
4 . 已知a∈R,函数
.
(1)当a=1时,解不等式
;
(2)若关于x的方程
的解集中恰有一个元素,求a的值;
(3)设a>0,若对任意
,函数
在区间
上的最大值与最小值的差不超过1,求a的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4f159847aac03a301d6ec4491ea49e3.png)
(1)当a=1时,解不等式
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5be1d8c6384d7fabddb693b2b7fcdf4a.png)
(2)若关于x的方程
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d83a42e14abde3584dc32d53f925c7ed.png)
(3)设a>0,若对任意
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/16443926c89badae2361d1290e4781b6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fe7d5809da02c15a43a0e9a898b9086.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c82dca4a0e082b5cbdb1beb6f4d1e2f1.png)
您最近一年使用:0次
2022-01-03更新
|
516次组卷
|
11卷引用:上海市普陀区长征中学2018-2019学年高三上学期期中数学试题
上海市普陀区长征中学2018-2019学年高三上学期期中数学试题上海市位育中学2017届高三上学期9月零次考试数学试题四川省乐山市2019-2020学年高一上学期期末数学试题上海市嘉定区第二中学2020-2021学年高一上学期第二次月考数学试题江苏省镇江市扬中高级中学2021-2022学年高一上学期12月月考数学试题上海市奉贤区致远高级中学2023届高三上学期10月月考数学试题广东省东莞市东莞第一中学2020-2021学年高一上学期第二次月考数学试题沪教版(2020) 25天高考冲刺 双新双基百分百24(已下线)专题19 函数解答题(文科)宁夏银川一中2020-2021学年高一上学期期中考试数学试题江苏省苏州市吴江中学2023-2024学年高一上学期12月月考数学试题
名校
5 . 已知函数
.
(1)计算
的值;
(2)设
, 解关于
的不等式:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d9a6064341667c54815c299cdc19984c.png)
(1)计算
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b17e5c8ba9972b9fdae02c354ce9f84.png)
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1e69392d21261afd8e5e5f096634669.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48857d079f55a8cb8ddb6a1276717533.png)
您最近一年使用:0次
2019-05-08更新
|
498次组卷
|
2卷引用:甘肃省张掖市山丹县第一中学2019-2020学年高一上学期9月月考数学试题
解题方法
6 . 设定义在R上的函数
,满足当
时,
,且对任意
,有
.
(1)求
;
(2)求证:对任意
,都有
;
(3)解不等式
;
(4)解方程
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08115d6d9f876dea921a4d32260ff1fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5be1d8c6384d7fabddb693b2b7fcdf4a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5ab4b75fa22deba7fcbcdcb31dd45b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ae291241c1f518f99a6dab5e1f6078a.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f54b6a060d6c51a328341df76013bd89.png)
(2)求证:对任意
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24a57996290794e082b21d8f1dfc322a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/018857ec6e498113b3b12a730d9313da.png)
(3)解不等式
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/25e6511b4caf3a816d122fdc2d3636a2.png)
(4)解方程
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97d827e942f1478917fd786877e89db4.png)
您最近一年使用:0次
7 . 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
2020高三·全国·专题练习
解题方法
8 . 对于三次函数
,给出定义:设
是函数
的导数,
是
的导数,若方程
有实数解
,则称点
为函数
的“拐点”.某同学经过探究发现:任何一个三次函数都有“拐点”;任何一个三次函数都有对称中心,且“拐点”就是对称中心.若
,请你根据这一发现.
(1)求函数
的对称中心;
(2)计算
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/75044e0301ef9def5c1a1c8e6f2cba77.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a4b04824a308519a61318a82aa97a05.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51c530f4b7491b95acb8ce3eef9aa09d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1fd30c0905092ba072a910dcbb50e44.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a4b04824a308519a61318a82aa97a05.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f6e32948c0d5bd76385fb9fc654622d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79b752f0f189e5d8666daea73e145dff.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0573a6bcc480a91a43126d01bc19eeae.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51c530f4b7491b95acb8ce3eef9aa09d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db46d62d4c778babb46a0a3d223384e5.png)
(1)求函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4fe7d5809da02c15a43a0e9a898b9086.png)
(2)计算
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9a13d2d0312240397dba62df19b953d.png)
您最近一年使用:0次
解题方法
9 . 已知函数
.
(1)当
时,若
,求
的取值范围;
(2)若定义在R上的奇函数
满足
,且当
时,
,求
在
上的函数表达式;
(3)对于(2)中的
,解关于
的不等式
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc391884cb2d4e69c318015ed1cc5724.png)
(1)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b550ee821ee1838384835e81fc34b67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8bdcb7a165e76ace36ec1bca0dfef31b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
(2)若定义在R上的奇函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4669810732b633b60dbeaf0bf57204f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1bd7a1f45776fc5187e58c34fe8e5b57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3e46371f310e03a153a1698aad9d4c5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1d1a94ea3c278c2197572cc1b7725b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4669810732b633b60dbeaf0bf57204f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a1417a39c99b1e6b489c7c033a0625af.png)
(3)对于(2)中的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4669810732b633b60dbeaf0bf57204f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c6f358b09c4ae8dded748ae8f431856.png)
您最近一年使用:0次
解题方法
10 . 若定义在
上的函数
对任意实数
、
恒有
,当
时,
,且
.
(1)求证:
为奇函数;
(2)求
在
上的最小值;
(3)解关于
的不等式:
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a43b2faa4f81f32d94612dce724e772b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.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/ab0c6f119137e1b6760d55956d99d963.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e541ea2f855f981c96207070683d388.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1c73a98c1b3504e09bfbe0db849b0d24.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36f247866d4020ed309d4e4d121ce445.png)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e99bebf8db0d314aacb2cb1f09bf48c.png)
(3)解关于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1146bd0832a76214c792d20eb3cda46e.png)
您最近一年使用:0次
2024-02-17更新
|
199次组卷
|
2卷引用:1号卷·A10联盟2022-2023学年(2022级)高一上学期11月期中联考数学(人教A版)