名校
解题方法
1 . 给出下列四个命题:
①若
,则
为等腰三角形;
②函数
的最大值为
;
③在
中,若
,则
的形状是钝角三角形;
④用篱笆围一个面积为
的矩形菜园,要使所用篱笆周长最短,则所用篱笆最短的周长是
.
其中正确的序号为__________ (注:把你认为正确的序号都填上)
①若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b883d9703a1deaf8dbc18097c6b8bb2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
②函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/89deb3ed56b145b87f4711a49b8ab094.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
③在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/272058608afabdb02a59321e1bffe344.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15c0dbe3c080c4c4636c64803e5c1f76.png)
④用篱笆围一个面积为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6711f79513b534982a9ada2b625e9fdd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/45c758c27bec97c234d1d818c40f3d3f.png)
其中正确的序号为
您最近一年使用:0次
解题方法
2 . 给出下列命题
(1)命题“
,
”的否定是“
,
”
(2)若
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b804002ee3d72ff947cfc8426f90047c.png)
(3)已知
,
,若
,则a的取值范围是![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a568a870b0c247e1abaf4bf65b83865.png)
其中正确命题的序号为( )
(1)命题“
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ad5fe274cfc8da2dacfb65801f344ac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9490565d4714ffcbadb26fdfca443856.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ccd7af9298cd5ff19d8866fedb42ec4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9490565d4714ffcbadb26fdfca443856.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08115d6d9f876dea921a4d32260ff1fb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b804002ee3d72ff947cfc8426f90047c.png)
(3)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d0820285d82c98efc92ee43db58418fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19f4cde12869125b1eebc2c6c8ae22cc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96f1ba0a1129741502600e47bf058c98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a568a870b0c247e1abaf4bf65b83865.png)
其中正确命题的序号为( )
A.(2)(3) | B.(2) | C.(1)(3) | D.(1)(2) |
您最近一年使用:0次
解题方法
3 . 判断正误(正确的填“正确”,错误的填“错误”)
(1)对任意
,
均成立.( )
(2)若
,则
.( )
(3)
异号时,
.( )
(4)当
时,
的最小值为2.( )
(1)对任意
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73254f32b6da29ecc32df2e9f87a4c97.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2bcce6eb3b38322059b6051ce600ee8b.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fde64f4d3c38e43fbdee24eadc4b0dd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6dfa55731858aaed472d94ba55af2cc4.png)
(3)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/632244ea6931507f8656e1cc3437d392.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/37006891004d02050e7c57db20af3981.png)
(4)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b27f27cbb8185c1974d715ff95f8801c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/13f40c24c64bbb0645fcf585f4e66872.png)
您最近一年使用:0次
解题方法
4 . 判断正误(正确的写“正确”,错误的写“错误”)
(1)若两个正数的和为定值,则它们的积有最大值.( )
(2)x∈R,则
的最小值是2.( )
(3)若x>0,则函数
的最小值等于
.( )
(4)已知函数
存在最大值,若不等式
恒成立,则
.( )
(1)若两个正数的和为定值,则它们的积有最大值.
(2)x∈R,则
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e60c0b7c58c3c45581dbca3e6dca34f1.png)
(3)若x>0,则函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01798070ecd1c824b0a8b8566625606e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/143aca2ea7b880e70eb3ecaedc5f9c50.png)
(4)已知函数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51c530f4b7491b95acb8ce3eef9aa09d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cbb1fa6b43e76575833ff732190cda49.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86e6b93427826fcbb48f8cdfc54fcb17.png)
您最近一年使用:0次
名校
解题方法
5 . 有这样一道利用基本不等式求最值的题:
已知
且
求
的最小值.
小明和小华两位同学都“巧妙地用了
”,但结果并不相同.
小明的解法:由于
所以![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1aa5eb4249cc659809767bb1650cfbe.png)
而
那么
则最小值为![](https://staticzujuan.xkw.com/quesimg/Upload/formula/474bd808b81bce2d61dc8b95d0c740b6.png)
小华的解法:由于
所以![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11c9fc2869dcc1ae6d913b5db300f43c.png)
而
则最小值为![](https://staticzujuan.xkw.com/quesimg/Upload/formula/172681503b639df2b7dac358af9e9b06.png)
(1)你认为哪位同学的解法正确,哪位同学的解法有错误?
(2)请说明你判断的理由.
已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c34c590f48c84fe471d1af522c343c59.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d575bf340fd6486b3173ba6adc7d027f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e85107c8abd4a977590d7c038ed127a.png)
小明和小华两位同学都“巧妙地用了
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5be97cd1c7111b654d87d8fbb63b6a84.png)
小明的解法:由于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d575bf340fd6486b3173ba6adc7d027f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1aa5eb4249cc659809767bb1650cfbe.png)
而
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c869e5b4206749e1bdac5d6a87353276.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83ad92003a4e0e1544d98a8748f20711.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/474bd808b81bce2d61dc8b95d0c740b6.png)
小华的解法:由于
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d575bf340fd6486b3173ba6adc7d027f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11c9fc2869dcc1ae6d913b5db300f43c.png)
而
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1a232ed285d1569176a42ea0b6bae746.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/172681503b639df2b7dac358af9e9b06.png)
(1)你认为哪位同学的解法正确,哪位同学的解法有错误?
(2)请说明你判断的理由.
您最近一年使用:0次
2021-10-21更新
|
371次组卷
|
3卷引用:甘肃省嘉峪关市第一中学2020-2021学年高一下学期期末数学试题