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)
您最近一年使用:0次
解题方法
2 . 如果
,则四点O,P,M,N一定共面.( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b3fcb4196d6b5832c787cfa3853fb02.png)
您最近一年使用:0次