NO.PZ2020010302000003
问题如下：
What two properties must a PMF satisfy?
解释：
A PMF must be non-negative and sum across the support of the random variable to 1.
老师好，“non-negative”是什么意思？
NO.PZ2020010302000003 问题如下 Whtwo properties must a PMF satisfy? A PMF must non-negative ansum across the support of the ranm variable to 1. two fining properties of probability0 =P(E) =1; P(E1)+P(E2)+......+P(En)=1,if E1、E2...En,is mutually anexhaustive.properties of PMF:non-negative;the sum across all value in the support of a ranm variable must one.一个是概率的性质，一个函数的性质，但好像一样，概率之和等于1的两个条件，函数不需要吗？
NO.PZ2020010302000003 问题如下 Whtwo properties must a PMF satisfy? A PMF must non-negative ansum across the support of the ranm variable to 1. PMF是什么
