解题方法
1 . 在棱长为1的正方体
中,过面对角线
的平面记为
,以下四个命题:
,使
;
②若平面
与平面
的交线为
,则存在直线
,使
;
③若平面
截正方体所得的截面为三角形,则该截面三角形面积的最大值为
;
④若平面
过点
,点
在线段
上运动,则点
到平面
的距离为
.
其中真命题的序号为____________ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83c09eec4e14a861af83d7828797d176.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b239e234d9ae31814af54bf27b7056ba.png)
②若平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58cc6184b191e6da43911e701121517e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d0c6947783608bd8f6dc7fdaadad2cb.png)
③若平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/821309f088a175c00dc0f4828334503d.png)
④若平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97c01fdc7bc471af0b264a04aef0823e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d8772aa893a9c1d40f714cb25701701.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15b78c047642924fe864028c81b1f49d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/827ccf0c04aa941ba20d5f4c6068b46b.png)
其中真命题的序号为
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解题方法
2 . 设
分别是四棱锥
侧棱
上的点.给出以下两个命题,则( ).
①若
是平行四边形,但不是菱形,则
可能是菱形;
②若
不是平行四边形,则
可能是平行四边形.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5d659d5601d47fc8e580788f8bfc2cab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7eb6099cb3d24e0096b6c2f7aa432abe.png)
①若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/632f2bf1cd0435041fa04b01901d1c8c.png)
②若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/632f2bf1cd0435041fa04b01901d1c8c.png)
A.①真②真 | B.①真②假 | C.①假②真 | D.①假②假 |
您最近一年使用:0次
2024-01-15更新
|
278次组卷
|
2卷引用:专题05 空间直线与平面-《期末真题分类汇编》(上海专用)
名校
3 . 若
,则称
是关于x,y的方程
的整数解.关于该方程,下列判断错误 的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a40c81308e49d61ac1e98b9ba48a6ab6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/23b4f86e48e2b0d63c1865c60ed1e4d1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc7a85679aac8db77ae690199c1dad7c.png)
A.![]() ![]() |
B.![]() ![]() |
C.![]() ![]() |
D.![]() ![]() |
您最近一年使用:0次
解题方法
4 . 已知下列五个命题:①若
为减函数,则
为增函数;②若
为增函数,则函数
在其定义域内为减函数;③函数
,
在区间
上都是奇函数,则
在区间
是偶函数;④一条曲线
和直线
的公共点个数是
,则
的值不可能是1;⑤函数
的图像关于直线
对称.其中真命题个数的是( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e58070e6887dac5da1e3b0d326f16499.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5bc06c224d29b8e3dfa49a341a30a06c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4669810732b633b60dbeaf0bf57204f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/604a187300e47ef2d6b772d1ac5cf4a3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7d19de9707f80fe0f6e6aad2406d31a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/604a187300e47ef2d6b772d1ac5cf4a3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62df3cc16ef5d1559bc43ec5b041052f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3c34492505db5dbedea8bc2420ab2320.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8ad6b4e7637324d814d7474f54951374.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b384412acba251d87902ab928902f16.png)
A.2 | B.3 | C.4 | D.5 |
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名校
5 . 课上我们学习了“
”符号和数学上陈述句
一些常用的否定形式
,实际上“若
,则
”为假命题可以表述为“至少存在特例
满足性质
,使
”,即我们常说的举反例.
(1)请利用上述逻辑语言说明以下两个命题为假:
①任何集合都不是空集的子集;②若
,则
;
(2)其他教材中有这样一种新命题的表述: 如果把命题“若
,则
”称为原命题,那么将其结论的否定作为条件,将其条件的否定作为结论,可以得到一个新命题“若
,则
”,我们称新命题为原命题的逆否命题.并且有一个非常强有力的结论:原命题与它的逆否命题是同真或同假的.请综合利用上述知识证明:对于正实数
,若
,则
;
(3)证明:原命题“若
,则
”与它的逆否命题“若
,则
”同为真命题或同为假命题.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2ef73aff3fe470e367f4af24fdfff3df.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d1c79d9d4f43ffb42f22c287058b5f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2303430b989c36a0c5380d64b3182690.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f2c566d4285f887b69c855f31849542.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e31113e042661f75628af5e3b2dc56f1.png)
(1)请利用上述逻辑语言说明以下两个命题为假:
①任何集合都不是空集的子集;②若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/52ddfcb6c5c9f8b50444386d7221154c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9138d5904f6ff2a48f29e820ce54e0e0.png)
(2)其他教材中有这样一种新命题的表述: 如果把命题“若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/130adfc0b77a1bb4046c19fc52d5fe78.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73d277dac920ea0456d486ea528332f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/632244ea6931507f8656e1cc3437d392.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/127a0d8c1c7d15ed40ec4b8bca0ebdf6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/485a2d99320384a0857b00ce9ab9e990.png)
(3)证明:原命题“若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5858ee1ce52b251816757257a11c29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d1c79d9d4f43ffb42f22c287058b5f6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73d277dac920ea0456d486ea528332f0.png)
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