我们知道,常数列{c}(c≠0)可以看成是等差数列,也可以看成是等比数列。也就是说,等差数列和等比数列只能在特殊的常数列时才“相同”,在一般情况下是不同的。但从运算的角度来看,它们有着共同的结构和对应的性质,这反映了这两个数列的共性和丰富的内涵。 1.通项公式的共性结构等差数列的通项公式是 a_n=a_1+(n-1)d =a_1+d+d+…+d (n-1个d) ①等比数列的通项公式是 We know that the constant column {c} (c ≠ 0) can be seen as an arithmetic sequence, and it can also be regarded as a geometric sequence. In other words, the arithmetic progression and the geometric progression can only be “identical” when they are in a special constant column, and they are different under normal circumstances. However, from the perspective of operations, they have a common structure and corresponding nature, which reflects the commonality and rich connotation of these two series. 1. The general formula of the general structure of the general term equation, etc., is a_n=a_1+(n−1)d =a_1+d+d+...+d (n−1d) 1 The general formula of the series is: