【摘要】 讨论了服从几何分布和指数分布的二维随机变量极值函数分布及数字特征等相关问题．除了都具有无记忆特性，服从几何分布和指数分布的随机变量的极值函数也具有分布结构相似的特点．给出二维随机变量的极值函数的期望和方差的计算公式，并且和协方差的定义做了比较．更多还原

【Abstract】 The distribution of extreme value functions and numerical characteristics of two-dimensional random variables that follow geometric and exponential distributions are discussed.In addition to having memoryless characteristics, the extreme value functions of random variables that follow geometric and exponential distributions also has similar distribution structures.The calculation formulas for the expectation and variance of the extreme value function of two-dimensional random variables were given,this formula are compared with definition of covariance.更多还原