GMAT – looking beyond the books – part I

By Abhijit
In Featured
Aug 10th, 2010
1 Comment
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GMAT Concepts - I GMAT Prep is not just about books. To prepare right, you must learn to look beyond the bookish concepts. In this series of short articles, I am going to talk about some interesting concepts which ScoreChase GMAT covers comprehensively in their courses but most books miss.

What is the difference between √x and (x)^1/2 ?

This is a very critical concept. There is a very crucial difference

Not many realize, GMAT Books are great only for the basics. For higher scores, you need to start looking at advanced concepts seldom covered by books.
between these two quantities which most GMAT test takers are unaware of.

√x : sign (the radical sign) is called the “Principal root” and always results in a non-negative number.

(x)^1/2: The x to the power of 1/2 is the result of the equation, y^2 = x. In this case the result could be “positive or negative or zero”.

So here is the conclusion

√x : Always non-negative

(x)^1/2: Can be positive or negative or zero

As in ScoreChase GMAT Workshops, we don’t believe a concept is complete without working on an example. Here is a question that will help you understand this topic a little bit better:

Q. For a negative integer x, what is the value of  x * √(x^2) ?
A) x^2
B) -x^2
C) x
D) -x
E) -1

Once you have found an answer. Please highlight the text below to see the solution

________________________

Since x is negative, -x will be positive
Since √(x^2) yields positive result and x is negative, the result will be -x
So, x*√(x^2) = x * -x = -x^2
(B)

________________________

Simple enough!

Stay tuned for more beyond the book concepts !

About ScoreChase:

ScoreChase GMAT provides online GMAT Preparation services to the GMAT Aspirants around the world. The courses range from Private Tutoring to Comprehensive Review to Crash Courses. If you have any questions, please contact us.

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One Response to “GMAT – looking beyond the books – part I”

  1. vaidehi says:

    a creative way to write the answer….good.

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