“+、-、×、÷”是数学中最基本的运算,但在数列中还是一种特殊的解题技巧,能有效地解决数列中的数学问题,并使其过程显得简捷明快.下面试从4个方面加以说明.一、“+”的技巧等差中项性质,数列求和中的倒序相加,求通项中的累加等,都包含了“+”的技巧.例1在等差数列an中,a1+a2 “+, -, ×, ÷” is the most basic operation in mathematics, but it is also a special problem-solving technique in the series, which can effectively solve the mathematical problems in the series and make the process simple and neat. Explained from four aspects. First, the “+” technique equals the nature of the difference, the reverse order in the summation of the series, and the addition in the general term, all contain the “+” technique. Example 1 Difference column an, a1+a2