新东方网络课堂:新gre数学重要考点汇总1 新版gre数学复习重要考点:Sum of Arithmetic Progression The sum of n-numbers of an arithmetic progression is given by S=nx*dn(n-1)/2 where x is the first number and d is the constant increment. example: sum of first 10 positive odd numbers:10*1+2*10*9/2=10+90=100 sum of first 10 multiples of 7 starting at 7: 10*7+7*10*9/2=70+315=385 remember: For a descending AP the constant difference is negative. 由于美国数学基础教育的难度增加导致数学考试越来越难,但新gre数学复习考点都是高中时候学到的知识点,考生不要过于紧张,把基本概念弄明白,再记住一些新版gre数学必备的词汇,那么相信新版gre数学应该没有问题。 |
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