数列是高中数学教学中的重点和难点,求数列通项是“数列”一章研究的主要问题。在求数列通项公式时,因为一般数列没有统一的通项公式,学生常因不得法而束手无策。在具体问题中,学生若能依据已知条件的特征,挖掘题目中隐含的信息,灵活选择方法进行转化,则可以有效突破这一重难点。本文举例说明求数列通项的常见几种方法,供读者参考。1已知S_n求a_n型例1(2007年高考数学广东卷)已知数列{a_n} The series is the key and difficult point in the mathematics teaching of high school. The main problem is to study the series general term is the chapter of the “number series”. When formulating general equations for numbers, because students do not have a universal general formula, students often do nothing to help them. In specific problems, students can effectively break through this difficult point if they can use the characteristics of known conditions, tap the information implicit in the topic, and flexibly select methods for conversion. This article gives an example of several common methods for obtaining general term numbers for readers’ reference. 1 Known S_n seeking a_n type case 1 (2007 college entrance examination mathematics Guangdong volume) known series {a_n}