新GRE數(shù)學(xué)考試重點(diǎn)介紹
自從新GRE改革以來，新GRE考試無論是在寫作、語文上還是數(shù)學(xué)上都有了很大的變化，以下便是新GRE數(shù)學(xué)考試重點(diǎn)介紹。
新版GRE數(shù)學(xué)復(fù)習(xí)重要考點(diǎn):Sum of Arithmetic ProGREssion
The sum of n-numbers of an arithmetic proGREssion is given by
S=nxdn/2
where x is the first number and d is the constant increment.
example:
sum of first 10 positive odd numbers:101+2109/2=10+90=100
sum of first 10 multiples of 7 starting at 7: 107+7109/2=70+315=385
remember:
For a descending AP the constant difference is negative.
由于美國數(shù)學(xué)基礎(chǔ)教育的難度增加導(dǎo)致數(shù)學(xué)考試越來越難，但新GRE數(shù)學(xué)復(fù)習(xí)考點(diǎn)都是高中時(shí)候?qū)W到的知識點(diǎn)，考生不要過于緊張，把基本概念弄明白，再記住一些新版GRE數(shù)學(xué)必備的詞匯，那么相信新版GRE數(shù)學(xué)應(yīng)該沒有問題。
AP
Average of n numbers of arithmetic proGREssion is the average of the
smallest and the
largest number of them. The average of m number can also be written as
x + d/2.
Example:
The average of all integers from 1 to 5 is /2=3
The average of all odd numbers from 3 to 3135 is /2=1569
The average of all multiples of 7 from 14 to 126 is /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/2,and the n-th number is s/m + d/2.
Example:
if the sum of 7 consecutive even numbers is 70, then the first number
x = 70/7 - 2/2 = 10 - 6 = 4.
the last number is 70/7+2/2=10+6=16.the 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+
AP:numbers from average
all m numbers of an AP can be calculated from the average. the first number
x = c-d/2, and the n-th number is c+d/2, where c is the
average of m numbers.
Example:
if the average of 15 consecutive integers is 20,
then the first number x=20-1/2=20-7=13 and
the last number is 20+1/2=20+7=27.
if the average of 33 consecutive odd numbers is 67,
then the first number x=67-2/2=67-32=35 and the
last number is 67+2/2=67+32=99.
Remember: 分頁標(biāo)題#e#
sum of the m numbers is cm,where c is the average.
以上便是新GRE數(shù)學(xué)考試重點(diǎn)介紹，各位考生可以根據(jù)自己的情況參考復(fù)習(xí)，預(yù)祝各位考生考試成功。
自從新GRE改革以來，新GRE考試無論是在寫作、語文上還是數(shù)學(xué)上都有了很大的變化，以下便是新GRE數(shù)學(xué)考試重點(diǎn)介紹。
新版GRE數(shù)學(xué)復(fù)習(xí)重要考點(diǎn):Sum of Arithmetic ProGREssion
The sum of n-numbers of an arithmetic proGREssion is given by
S=nxdn/2
where x is the first number and d is the constant increment.
example:
sum of first 10 positive odd numbers:101+2109/2=10+90=100
sum of first 10 multiples of 7 starting at 7: 107+7109/2=70+315=385
remember:
For a descending AP the constant difference is negative.
由于美國數(shù)學(xué)基礎(chǔ)教育的難度增加導(dǎo)致數(shù)學(xué)考試越來越難，但新GRE數(shù)學(xué)復(fù)習(xí)考點(diǎn)都是高中時(shí)候?qū)W到的知識點(diǎn)，考生不要過于緊張，把基本概念弄明白，再記住一些新版GRE數(shù)學(xué)必備的詞匯，那么相信新版GRE數(shù)學(xué)應(yīng)該沒有問題。
AP
Average of n numbers of arithmetic proGREssion is the average of the
smallest and the
largest number of them. The average of m number can also be written as
x + d/2.
Example:
The average of all integers from 1 to 5 is /2=3
The average of all odd numbers from 3 to 3135 is /2=1569
The average of all multiples of 7 from 14 to 126 is /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/2,and the n-th number is s/m + d/2.
Example:
if the sum of 7 consecutive even numbers is 70, then the first number
x = 70/7 - 2/2 = 10 - 6 = 4.
the last number is 70/7+2/2=10+6=16.the 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+
AP:numbers from average
all m numbers of an AP can be calculated from the average. the first number
x = c-d/2, and the n-th number is c+d/2, where c is the
average of m numbers.
Example:
if the average of 15 consecutive integers is 20,
then the first number x=20-1/2=20-7=13 and
the last number is 20+1/2=20+7=27.
if the average of 33 consecutive odd numbers is 67,
then the first number x=67-2/2=67-32=35 and the
last number is 67+2/2=67+32=99.
Remember: 分頁標(biāo)題#e#
sum of the m numbers is cm,where c is the average.
以上便是新GRE數(shù)學(xué)考試重點(diǎn)介紹，各位考生可以根據(jù)自己的情況參考復(fù)習(xí)，預(yù)祝各位考生考試成功。
