在物理解题中 ,常常会求一些物理量的极大值和极小值 .物理量的极值在物理问题中往往具有特殊的意义 ,有时会显得非常重要 .下面就简单介绍一下物理解题中常用的求极值的方法 .1　和为定值的函数极值n个正数的和为定值k ,则当此n个正数相等时其积有最大值 (kn) n.例 1 .把电量 In the matter comprehension question, some maximal and minimum values ​​of physical quantities are often sought. The extremum of physical quantities often has special meaning in physical problems, and sometimes it is very important. Here is a brief introduction of common understanding problems. The method of seeking extremum and the sum of the extreme values ​​of the fixed-valued function n are the fixed value k, then the product has the maximum value (kn) when the n positive numbers are equal. n. Electricity