文氏图是集合语言中的图象语言,它易引起清晰的视觉形象,能直观地表达概念、问题的本质以及相互之间的关系,在抽象的数学思维面前,起着具体化和帮助理解作用,因此运用得法,可达到简缩思维过程的目的,摆脱思维受阻的困境,从而能产生妙解.一、求抽象的集合运算问题例1已知集合A,B The Venn diagram is an image language in a set language. It can easily lead to a clear visual image, intuitively express the concept, the nature of the problem, and the relationship between each other. In the face of abstract mathematics, it is embodied and helpful to understand. The role, therefore, can be used to achieve the purpose of concise thinking process, get rid of the predicament of blocked thoughts, which can produce wonderful solutions. First, the abstract set of calculation problems Example 1 Known set A, B