标题: 难题求助！ [打印本页] 作者: 董琰怡 时间: 2013-9-7 19:11 标题: 难题求助！ an arithmetic sequence is a sequence in which each term after the first is equal to the sum of the preceding term and a constant. 这句话到底应该怎么理解啊。。。 作者: wdxb_shen 时间: 2013-9-7 19:16
等差数列后一项等于前一项加一个常数