在高三数列专题复习中,求数列的通项与前n项和历来是重点,也是学生普遍感到困难的地方。虽然在复习讲义中归纳了不同类型的各种解题方法,但是在实际练习或考试中,学生还是不能顺利、完整地写出准确答案,或是漏掉讨论n=1的情况,或是计算环节出现失误导致错误。针对学生计算能力弱的问题,笔者利用待定系数法来确定几种常见题型的标准答 In the Third Plenary Specialist Review, the general term and the first n terms in the numerical series have always been the focus of attention. They are also places where students find it generally difficult. Although various types of problem-solving methods are summarized in the review notes, students still can not write accurate answers in actual exercises or tests, omit the discussion of n = 1, or calculate Link errors led to errors. For students with weak ability to calculate, I use the coefficient to be determined to determine the standard of several common questions