Questions about the world of GRE Math from other sources and general math related questions.
baily106
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Fractional Exponents

by baily106 Fri Aug 08, 2014 6:18 am

Hello,

Would X raised to 2/3 = 4 simply mean take the third square of x and then square it? This would mean X is 2 correct?
Any special rules/situations for fractional exponents we should know/be aware of?

Thanks.
enphilus
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Re: Fractional Exponents

by enphilus Fri Aug 08, 2014 4:06 pm

Hi, just so you know, it's not "third square", it's actually called third root or fourth root as the case may be. Considering your example, it will be the third root of the square of x =4. To find x, simply take the third root of 4 and then square it. Thus, x will be 2.5
tommywallach
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Re: Fractional Exponents

by tommywallach Sat Aug 09, 2014 10:34 pm

Hey Baily,

Enphilus is right: it's called the cube root.

One thing to add: the order in which you do the two things is irrelevant. For example:

8 ^ 2/3 =

EITHER The cube root of "8^2", which is the cube root of 64, which is 4

OR the cube root of 8, then square THAT. The cube root of 8 is 2, and 2^2 = 4.

Hope that helps!

-t
baily106
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Re: Fractional Exponents

by baily106 Tue Aug 12, 2014 5:50 am

Both pieces of information are helpful; thank you.
Anisha
tommywallach
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Re: Fractional Exponents

by tommywallach Wed Aug 13, 2014 10:42 pm

Cool!

-t