数列是高中数学很重要的内容之一,数列中的求通项是最常见的题型,其形式多样,解法灵活,也是近年高考考查的重点内容.本文介绍几种常用的求数列通项的方法,供参考.1叠加法例1(2003年全国高考试题)已知数列{an}满足a1=1,an=3n-1+an-1(n≥2).(1)求a2、a3;(2)证明:an=3n-12.解(1)易 The series is one of the most important contents of the high school mathematics. The solution items in the series are the most common questions. The forms are various and the solution is flexible, which is also the key content of the college entrance examination in recent years. This article introduces several commonly used general number items. Method, for reference. 1 Superposition Law 1 (2003 National Examination Questions) Known series {an} satisfies a1=1, an=3n-1+an-1(n≥2). (1) find a2, a3; (2) Proof: an=3n-12. Solution (1) Easy