“极端性”原理是解决数学问题的一个重要方法,从极端情形(最大值、最小值、极端有利、极端不利、边界情形、极端位置等)入手分析,往往能发现解决问题的突破口.此法不仅在解竞赛问题中用途广泛.事实上,在平时的解题过程中,为了寻求更清晰的解题思路,更简洁的运算方法,我们也会不经意地去“走极端”,本文例举说明. The “extreme” principle is an important method to solve mathematical problems. From the analysis of extreme situations (maximum, minimum, extreme favorable, extremely unfavorable, boundary conditions, extreme positions, etc.), it is often possible to find breakthroughs in solving problems. Not only is it widely used in solving competition problems. In fact, in the process of solving problems in peacetime, in order to seek clearer ideas and more concise calculation methods, we will inadvertently go “extremely extreme”. .