所谓构造法是指先构造一个与待证结果有关的辅助函数或是命题,再利用已知条件及有关概念、定理推理得出所要证明的结果.它具有两个显著的特性,即直观性和可行性.正是这两个特性,使构造法在求解数学问题中得到广泛的运用.构造法在开拓学生的思维,培养学生的创新能力方面独具匠心.一、构造法解题的实质1.解决“存在性”问题所谓存在性问题,是指结论中含有“存在”一词的问题, The so-called construction method is to construct a auxiliary function or proposition related to the result to be certified, then use the known conditions and related concepts to derive the result to be proved by the theorem inference, which has two salient features: intuitiveness and feasibility It is these two characteristics that make the construction method widely used in solving mathematical problems.The construction method has its originality in exploiting the students ’thinking and in cultivating the students’ innovative ability. The “existential” problem The so-called existential issue refers to the problem that the conclusion contains the word “existence”