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Why does ETS change the rules?
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01 Feb 2019, 17:08
01 Feb 2019, 17:08
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I have noticed that ETS does not keep consistent how it treats results of square roots. For example:
Q: If (X+3)^2 = 225, which of the following could be the value of x-1?
A: correct answer is -19 and the assumption is square root of 225 is both 15 and -15
Q2: Which is bigger between the two? squareroot(7) + squareroot(11) OR squareroot(3) + squareroot(15)
A2: I thought the answer would be D as in the relationship cannot be figured out since any of the square roots can be a negative and we do not know which is which
Any thoughts on when to explore a negative answer to a square root problem v. when to not?
Q: If (X+3)^2 = 225, which of the following could be the value of x-1?
A: correct answer is -19 and the assumption is square root of 225 is both 15 and -15
Q2: Which is bigger between the two? squareroot(7) + squareroot(11) OR squareroot(3) + squareroot(15)
A2: I thought the answer would be D as in the relationship cannot be figured out since any of the square roots can be a negative and we do not know which is which
Any thoughts on when to explore a negative answer to a square root problem v. when to not?
Re: Why does ETS change the rules?
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02 Feb 2019, 03:21
02 Feb 2019, 03:21
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Expert Reply
Hi,
please, could you post the questions in their entirety as a separate post under the right section of quant ??
Thank you so much.
Regards
please, could you post the questions in their entirety as a separate post under the right section of quant ??
Thank you so much.
Regards
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Re: Why does ETS change the rules?
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24 Mar 2019, 22:09
24 Mar 2019, 22:09
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Expert Reply
ETS is consistent in the rule--it's just a rather quirky math rule.
Here's the rule: IF YOU SEE THE ROOT SYMBOL, THEN TAKE THE POSITIVE ROOT ONLY.
For example, the square root of 9 is positive 3 only even though -3^2 = 9
However, if the question says x^2 = 9 then the answer can either be -3 or +3.
-Brian
Here's the rule: IF YOU SEE THE ROOT SYMBOL, THEN TAKE THE POSITIVE ROOT ONLY.
For example, the square root of 9 is positive 3 only even though -3^2 = 9
However, if the question says x^2 = 9 then the answer can either be -3 or +3.
-Brian
