数列是高中数学的重要内容之一 ,又是今后学习高等数学的基础 ,因此成为历年高考考查的重点与热点 .本文就数列问题中的几类易错题进行分类解析 ,仅供参考 .1　 忽略 n的取值范围导致错误例 1　已知 {an}是递增数列 ,且对于任意的正整数 n,an =n2 +λn恒成立 ,求实数λ的取值范 The series is one of the important contents of high school mathematics, and it is also the basis for studying advanced mathematics in the future. Therefore, it has become the focus and hotspot of the previous college entrance exams. This article classifies and analyzes several types of error-prone problems in the series of questions. It is for reference only. The value range of n causes the error. Example 1 It is known that {an} is an increasing sequence, and for any positive integer n, an = n2 + λn is constant, and the real number λ is taken as a value range.