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fractional and negative indices

what is the value of 25 1/2
251=2512⋅2512\displaystyle 25^{1} = 25^{\frac {1} {2}} \cdot 25^{\frac {1} {2}}

Does that kinda give you a hint?
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Angel28
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Original post by fudgey14
what is the value of 25 1/2


Hi,

An easy way to think of it is like this:
The top number of the fraction (numerator) is to do with squaring, cubing, etc. and the denominator to do with square root, cube root etc.
So if it was 16 to the power 5/4 it means do 16 to the power 5 and fourth root. So fourth root of 16 is 2 and then to the power 5 is 32.
Hope this wasn't confusing!
Reply 3
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fudgey14
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Original post by Angel28
Hi,

An easy way to think of it is like this:
The top number of the fraction (numerator) is to do with squaring, cubing, etc. and the denominator to do with square root, cube root etc.
So if it was 16 to the power 5/4 it means do 16 to the power 5 and fourth root. So fourth root of 16 is 2 and then to the power 5 is 32.
Hope this wasn't confusing!
thank you for your reply get the first bit but the last bit to get 2 im confused :frown:
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Angel28
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Original post by fudgey14
thank you for your reply get the first bit but the last bit to get 2 im confused :frown:


You mean you don't understand the denominator bit?
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fudgey14
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Original post by Angel28
You mean you don't understand the denominator bit?

yes the last bit the fourth denominator that it is 2 i supposed im confused has i am looking at my equation thanks for you help though
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Angel28
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Original post by fudgey14
yes the last bit the fourth denominator that it is 2 i supposed im confused has i am looking at my equation thanks for you help though


I was using a different example:16 ^ 5/4. The bottom number of the fraction, which in my example is 4 is to do with the root. So the four means you do the fourth root. If you do the fourth root of 16 on your calculator you will get 2 because 2 x 2 x 2 x 2 is equal to 16. You then do 2 to the power 5 (which deals with the top number of the fraction) to get 32.

If the bottom number of the fraction was 3 for example, you would do cube root.

Do let me know whether you understand or not!
(edited 8 years ago)
Reply 7
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fudgey14
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Original post by Angel28
I was using a different example:16 ^ 5/4. The bottom number of the fraction, which in my example is 4 is to do with the root. So the four means you do the fourth root. If you do the fourth root of 16 on your calculator you will get 2 because 2 x 2 x 2 x 2 is equal to 16. You then do 2 to the power 5 (which deals with the top number of the fraction) to get 32.

If the bottom number of the fraction was 3 for example, you would do cube root.

Do let me know whether you understand or not!

sorry i seemed confused really got to me i just didn't get it i will try my equations now and let you know thanks again you've been an awesome help :smile:
Reply 8
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Angel28
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Original post by fudgey14
sorry i seemed confused really got to me i just didn't get it i will try my equations now and let you know thanks again you've been an awesome help :smile:


No problem at all! More than happy to help! :smile:

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