北京市高中数学竞赛2001、2002、2003年,连续三年出现一类多变量函数双重最值问题,题目如下: 例用max{x1,x2,x3,…,xn}表示实数x1,x2,x3,…,xn中的最大值,用min{x1,x2,x3,…,xn)表示实数x1,x2,x3,…,xn中的最 In the Beijing High School Mathematics Contest in 2001, 2002, and 2003, there was a double-valued problem for a class of multivariable functions for three consecutive years. The topics are as follows: For example, max{x1,x2,x3,...,xn} represents a real number x1,x2,x3 The maximum value of ,...,xn, using min{x1,x2,x3,...,xn) to represent the most significant of the real numbers x1,x2,x3,...,xn