数列是历届高考的重点 ,在试题中的比重约占总分的 1 0 % .现就近几年高考数列题的速解技巧归结如下 ,供同学们复习参考 .一、巧取特例1 取自然数列ａｎ =ｎ例 1　 (1 993年全国高考题 )已知等差数列{ａｎ},公差ｄ 0 ,ａ1 0 ,Ｓｎ = ｎｉ=11ａｉａｉ+1 ,则ｌｉｍｎ→∞Ｓｎ The series is the focus of previous college entrance examinations and accounts for about 10% of the total scores in the examination questions. The quick solutions for the college entrance exams in recent years are summarized as follows for the students to review the references. 1. Take the special case 1 Take the natural sequence An = n Case 1 (National Entrance Examination in 1993) Known series of equal {an}, Tolerances d 0, a1 0, Sn = ni=11aiai+1, then limn→∞Sn