文[1]在讲解立体几何存在性探索问题时,讲到:对于此类问题,一般采用先猜后证的解题思路.其实,这种想法是不对的.事实上,确有不少同学在解决这类问题时会猜特殊位置(尤其是中点)去验证,如果能验证出,则问题解决,否则就陷入猜来猜去也猜不明白的误区.而资料上解决这类问题都是先下结论后证明,没有思路分析,因此, In [1], when explaining the problem of the existence of three-dimensional geometric exploration, we talked about: For such problems, we usually adopt the idea of ​​solving the problem after guessing the evidence. In fact, this idea is wrong. In fact, there are indeed many students. When solving such problems, we will guess the special position (especially the midpoint) to verify. If it can be verified, then the problem will be solved, otherwise we will fall into the guesswork to guess or guess, and to solve this kind of problem on the data It is the first conclusion that proves that there is no analytical analysis. Therefore,