恒成立与存在性问题是高中数学中常见的一种题型,基于学生的认知水平对这种题型的理解比较吃力,特别是一题中恒成立与存在性问题同时出现时,学生更不容易把已知条件演绎出来,针对这一困惑点,通过对一道题的多种变式讲解,让学生对这类问题的认识更上一层楼. Constantly established and existential problems are common in high school mathematics, a type of questions, based on the cognitive level of students on this type of problem-solving is more difficult, especially in a problem of constant establishment and existence of problems simultaneously, the students more It is not easy to deduce the known conditions. In response to this confusing point, through a variety of explanations on a single question, students are expected to further their understanding of such issues.