解题方法
1 . 已知命题
:“若
,则二次不等式
无解”.
(1)写出命题
的否命题;
(2)判断命题
的否命题的真假.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46ede301b85065e628f196f19b0c7675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b5f28031b036e4a37be931d5ff28368.png)
(1)写出命题
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
(2)判断命题
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
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2 . 已知
:
,
:
.
(1)若
是
的必要不充分条件,求实数
的范围;
(2)若
是
的必要不充分条件,求实数
的范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9403c598bbb48468b9a9ab662f24e793.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9aa8a716a31b0f51b70fdf9bdb257909.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ed08e1bc01a2f627164e7fce8ff0e03.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9aa8a716a31b0f51b70fdf9bdb257909.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b1010846eeec6c9da29640f5aa3f8738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3e442eb9fae52d740b600bff0ee4aa9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6659e3aec36b969f21633c5efe3ac46.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
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3 . 分别写出下列命题的逆命题、否命题、逆否命题.
(1)垂直于同一个平面的两条直线平行;
(2)设
,
,
,
是实数,若
,
,则
.
(1)垂直于同一个平面的两条直线平行;
(2)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c02bc0c74292b1e8f395f90935d3174.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f22fec5a381ae8aca93d876e54c79de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd031c16a5cbeb1bab9f913d2ad2cfd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3538c7b7aa12ff28d4d06ab400ebaaad.png)
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4 . 写出命题“已知,a b 是实数,若ab=0,则a=0或b=0”的逆命题,否命题,逆否命题,并判断其真假.
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名校
5 . (1)写出命题“若两个三角形是全等三角形,则它们面积相等”的逆命题,否命题及逆否命题;
(2)求下列函数的导数.
①
;
②
.
(2)求下列函数的导数.
①
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3f7590ae86790e6ca2417ad55d397441.png)
②
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a11a6960d436ae3c739e047fb0e56c81.png)
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6 . 写出下列命题的逆命题、否命题以及逆否命题:
(1)若
,则
;
(2)已知
为实数,若
,则
.
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00ee4849f60afce5a3a85ccd492314e2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0219e415740558b6d03038c91c9f3689.png)
(2)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d10449bc77d692a7270e0f20a68cdf2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/648bb8829ffc34b7b466b1bb05777103.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0af27075a29a658a88bec069fe4804da.png)
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20-21高二·全国·单元测试
7 . 分别写出下列命题的逆命题、否命题、逆否命题.
(1)垂直于平面α内无数条直线的直线l垂直于平面α;
(2)设a,b,c,d是实数,若a=b,c=d,则a+c=b+d.
(1)垂直于平面α内无数条直线的直线l垂直于平面α;
(2)设a,b,c,d是实数,若a=b,c=d,则a+c=b+d.
您最近一年使用:0次
20-21高二·全国·单元测试
8 . 分别写出下列命题的逆命题、否命题和逆否命题,并判断其真假.
(1)若实数a,b,c成等比数列,则b2=ac;
(2)函数y=logax(a>0且a≠1)在(0,+∞)上是减函数时,loga2<0.
(1)若实数a,b,c成等比数列,则b2=ac;
(2)函数y=logax(a>0且a≠1)在(0,+∞)上是减函数时,loga2<0.
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9 . 已知:条件p:实数t满足使对数
有意义;条件q:实数t满足不等式![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6bd13dd1c7571a05cf46e9e64e79f5fa.png)
.
(1)已知
,命题:若p,则q,请写出它的否命题,并判断它们的真假;
(2)若p是q的充分不必要条件,求实数a的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a5dd85ae1c2556710cf37801f9e4d7a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6bd13dd1c7571a05cf46e9e64e79f5fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e37708a68d0ca72413ada85d01d2ed19.png)
(1)已知
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b550ee821ee1838384835e81fc34b67.png)
(2)若p是q的充分不必要条件,求实数a的取值范围.
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10 . 写出命题“若m<1,则一元二次方程x2 +x+m=0有实数解”的逆命题、否命题和逆否命题,并判断它们的真假.
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