1 . 已知
,试判断下列结论是否正确:
(1)![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf14cecd098daeef5fcbe63901288366.png)
( )
(2)![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba18dd2bb7c0000cf6aa1bde4fca315e.png)
( )
(3)![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdcc9d7e6ac0b39993a92afe0d8ecf9e.png)
( )
(4)![](https://staticzujuan.xkw.com/quesimg/Upload/formula/926a7bc06029feff54757c15de5a67db.png)
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3de5db5c2e41cfbfc0436e7190778803.png)
(1)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bf14cecd098daeef5fcbe63901288366.png)
(2)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba18dd2bb7c0000cf6aa1bde4fca315e.png)
(3)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdcc9d7e6ac0b39993a92afe0d8ecf9e.png)
(4)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/926a7bc06029feff54757c15de5a67db.png)
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2 . 判断下列说法是否正确:
(1)设点O为四边形ABCD所在平面内一点,若
,则四边形ABCD为平行四边形;( )
(2)在矩形ABCD中,
.( )
(1)设点O为四边形ABCD所在平面内一点,若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/984a33fc2ae4a24623bd8d5b634b29a5.png)
(2)在矩形ABCD中,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8de8984eb01e1eaa16b01ceb2077ff10.png)
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解题方法
3 . 如果
,则四点O,P,M,N一定共面.( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b3fcb4196d6b5832c787cfa3853fb02.png)
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4 . 若
,则A,B,C,D四点共线.( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1da65df9df70430d0a095297a628f04c.png)
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5 . 若
,则λ=0或![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a57a47c35195783f2eba8c6fd6649594.png)
( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6ebb215e473c34199bff42cc214cd41.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a57a47c35195783f2eba8c6fd6649594.png)
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