数列是高中数学的重点和难点问题,也是高考查的重点内容.由于它是一种特殊的函数,因此解题的过程中,我们经常会用到一些函数的思想法,其中待定系数法求数列的通项就是一种非常错的思想方法.尤其是在已知数列的递推关系式数列的通项问题上的应用,一般先运用待定系数构造一个新的递推关系式,然后与原递推关系式的对应系数相等,从而解决问题. Series is the high school mathematics focus and difficult issues, but also the key content of the college entrance examination.As it is a special function, so the process of solving problems, we often use the idea of ​​function of some of the law, Is a very wrong way of thinking.Especially in the known sequence of recursive relational series of general problems on the application of the general use of undetermined coefficients to construct a new recursive relation and then with the original delivery Push the corresponding coefficient of the equivalent, so as to solve the problem.