GRE考试技巧关于数学重要考点AP介绍
新GRE考试技巧:数学重要考点AP
新gre考试实施以来,不仅对写作部分茫然不知所措,就连我们所擅长的数学也甚是担忧,相信这其中的`原因还是由于考生在新gre数学复习时没有把基础打牢。如果新版gre数学基本考点都没有复习到,如何能拿到分数呢?所以说,想要新版gre数学考好,复习的时候一定要把基本概念和重要考点都弄扎实。 天针对新版gre数学复习,小编给大家整理的是关于平均数的相关内容,这些概念在考试中一定会考到的。希望考生能再接再厉,取得一个好成绩,突破新版gre数学难的困境。
AP
Average of n numbers of arithmetic progression (AP) is the average of the smallest and the largest number of them. The average of m number can also be written as x + d(m-1)/2.
Example:
The average of all integers from 1 to 5 is (1+5)/2=3
The average of all odd numbers from 3 to 3135 is (3+3135)/2=1569
The average of all multiples of 7 from 14 to 126 is (14+126)/2=70
remember:
Make sure no number is missing in the middle.
With more numbers, average of an ascending AP increases.
With more numbers, average of a descending AP decreases.
AP:numbers from sum
given the sum s of m numbers of an AP with constant increment d, the numbers in the set can be calculated as follows:
the first number x = s/m - d(m-1)/2,and the n-th number is s/m + d(2n-m-1)/2.
Example:
if the sum of 7 consecutive even numbers is 70, then the first number x = 70/7 - 2(7-1)/2 = 10 - 6 = 4.
the last number (n=m=7)is 70/7+2(2*7-7-1)/2=10+6= set is the even numbers from 4 to 16.
Remember:
given the first number x, it is easy to calculate other numbers using the formula for n-th number: x+(n-1)
AP:numbers from average
all m numbers of an AP can be calculated from the average. the first number x = c-d(m-1)/2, and the n-th number is c+d(2n-m-1)/2, where c is the average of m numbers.
Example:
if the average of 15 consecutive integers is 20, then the first number x=20-1*(15-1)/2=20-7=13 and the last number (n=m=15) is 20+1*(2*15-15-1)/2=20+7=27.
if the average of 33 consecutive odd numbers is 67, then the first number x=67-2*(33-1)/2=67-32=35 and the last number (n=m=33) is 67+2*(2*33-33-1)/2=67+32=99.
Remember:
sum of the m numbers is c*m,where c is the average.
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。
-
GRE填空题:解析GRE12年填空题考试技巧
GRE填空题:解析GRE12年填空题最新考试技巧Atseveralpointsinhisdiscussion,Graves,ineffect,----------evidencewhenitdoesnotsupporthisargument,tailoringittohisneeds.(A)addresses(B)creates(C)alters(D)suppresses(E)substitutes中华考试网〖解答〗句末的...
-
GRE阅读提升的6个原则
想要提升GRE阅读水平,就需要做到化被动被主动。今天小编就给大家带来GRE阅读成绩提升的六大原则,赶紧一起来学习一下吧!一、带着问题看文章。上面说了不要先看题目,为什么这里又要说带着问题看文章呢?这里的问题,其实是指的一些常见的容易出题点,再看文章的过程中,主...
-
14个GRE词汇记忆方法技巧
14个GRE词汇记忆方法技巧:1.每天睡前小结一下当天背词的心得体会,以后才能越背越顺。2.第一遍坚持杨鹏的循环方法,一定要把每个步骤做到,做好;如果每天时间不充裕可采用26天,每天2个list的方法。3.第一遍不要管英义、派生、同根、同义反义等项,着重记忆主词条、中义...
-
gre考试填空题的应用技巧有哪些
相对于GRE阅读来说,GRE填空题是可以下功夫得高分的一种题型,在GREverbal每个section的38道题当中,填空题占了7道题。下面我们一起来看一下GRE填空题满分解题技巧。在谈GRE填空题技巧之前要注意自己的基础,首先是词汇是基础,记住GRE词汇书上的百分之八、九十的词汇;...