极限,是高等数学中最重要、最基本的概念.它是一条主线,贯穿于高等数学的始终——连续、导数、积分等概念都是由它来定义的;它是从静止认识运动,从近似认识精确,从有限认识无限的一种数学方法.然而,极限的“ε—N”和“ε—δ”定义,以其严密的逻辑形式,纯粹的数学语言,高度的抽象概括,往往使学生难以接受,不得要领. The limit is the most important and basic concept in higher mathematics. It is a main line that runs through higher mathematics. The concepts of continuity, derivative, and integral are all defined by it; it is a movement from standstill, from Approximation knows precisely, a mathematical method that is infinitely limited from the point of view of knowledge. However, the limits of the definition of “ε-N” and “ε-δ”, in their strict logical form, purely mathematical language, highly abstract, often make Students are hard to accept and have no way to get to.