全概率公式教学方法研究

Research of Teaching Method of the Whole Probability Formula

:全概率公式是概率教学中的一个难点 ,在概率计算中 ,有时要综合利用加法公式和乘法公式才能解决问题 ,这就是全概公式。对于一个较复杂的事件 B,使用全概率公式的关键就是能找到一个伴随着 B发生的完备事件组 A1 ,A2 ,… ,An,将所讨论的事件划分为若干个互不相容的“简单”事件 ,而这些“简单”事件的概率又相对较容易求 ,进而即可得最后结果。本文通过对一些典型题目的分析研究 ,归纳总结出求解此问题的分析方法、解题步骤 ,以使学生理解、掌握全概率公式 。

The whole probability formual is a difficult point in the probability teaching. We sometimes comprehensive utilization formula of addition and multiplication to solve problems in the probability counting. This is the whole probability formula. To a rather complecated incident B the key of using the whole probobility formula is to find out a group of complete incident A 1, A 2, …, A n with the happening B. We make the incident that we discussed devided into a number of simple incident of interdepandant. And these probability of simple incident is rather more easy to beg and then it can get the finally results. This text sum up the analyse method and step to solve problems through researching some model title subject. So that the students can understand and master the whole probability formula and to use it correctly to solution of problems in reality.