Hi,
I was reading Master the GMAT maths concepts about square root. According to it, GMAT only consider positive value of square root. For example-
4th root of 16 = -2 or 2
GMAT only consider 2. Isn't it wierd ?
Can any expert please comment on this?
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Square root concept in GMAT
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Frankenstein
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Hi,
It is not just on GMAT. Square root of number is always the positive one. Never consider the negative root.
sqrt(4) = +2 only, not 2 or -2.
Some of the school books might have given both roots. But, it is incorrect.
But, if you are given x^2 = 4, find x. The answer would be x =+2 or -2.
It is not just on GMAT. Square root of number is always the positive one. Never consider the negative root.
sqrt(4) = +2 only, not 2 or -2.
Some of the school books might have given both roots. But, it is incorrect.
But, if you are given x^2 = 4, find x. The answer would be x =+2 or -2.
Cheers!
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BlindVision
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If I may add the obvious, no number when multiplied an even number of times will yield a negative number.
However, for odd roots (cube, 5th, 7th, etc.) the root will have the same sign as the base:
3 sqrt(-27) = -3 not +/- 3
However, for odd roots (cube, 5th, 7th, etc.) the root will have the same sign as the base:
3 sqrt(-27) = -3 not +/- 3
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tpr-becky
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If the GMAT puts the number under the square root then they only consider the positive root.
Thus sqrt25 = 5
However if the gmat says the square of a number is -- then you need to consider positive and negative.
Thus x^2 = 25 means that x = 5 or -5
Thus sqrt25 = 5
However if the gmat says the square of a number is -- then you need to consider positive and negative.
Thus x^2 = 25 means that x = 5 or -5
Becky
Master GMAT Instructor
The Princeton Review
Irvine, CA
Master GMAT Instructor
The Princeton Review
Irvine, CA
