You may be wondering how to use Excel to derive different roots of a number. Finding a square root is easy: you just use the SQRT function. For instance, the following returns the square root of the value in cell B7:
=SQRT(B7)
What about different roots, however? What if you want the fifth root of the value in B7, instead of the square root? Unless you are a math whiz (and I am not), the answer may not be that obvious. All you need to do is raise the value to the power of 1/n. For instance, if you want that fifth root of B7, then you would use the following formula:
=B7^(1/5)
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2020-11-13 06:46:18
Peter Atherton
Ronald Finnerty
A couple of useful links'
https://www.exploringbinary.com/binary-converter/
https://indepth.dev/the-simple-math-behind-decimal-binary-conversion-algorithms
Unfortunately, neither how to get the square root of a binary number. Here are the basics:
(see Figure 1 below)
You can convert a whole number to binary using the DEC2BIN function or by an algorithm shown in Fig1. It also shows how to convert a decimal to binary. Some decimals can not be converted exactly, so we stop when you get a repeated pattern.
For the decimal algorithm, you can use the TEXTJOIN function to get the decimal part from the algorithm.
To get a square root you can use the Babylonian algorithm {fig2), I just used the SQRT function in K2 of 65 to get the integer binary. And used a version of the TEXTJOIN for the decimal part.
(see Figure 2 below)
Of course, you don't need the Babylonian algorithm for the fraction just get it from the decimal SQRT function.
Figure 1. Integer & Faction convertsion.
Figure 2. Babylonian Fraction Algorithm
2020-11-12 05:47:03
JMJ
I'm afraid there is serious confusion here:
- n^(1/5) gives the fifth root of n
- n^-(5 ) gives the inverse of n^5
By example, if n = 10,
n^2 = 100
n^-2 = 0.01
n^(1/2) = 3.16227766 (this is the square root of 10)
So, using fractional exponents or negatives exponents is COMPLETELY DIFFERENT !
2017-09-25 10:20:04
Ronald Finnerty
this did not answer the finding nth root question. It merely shows how nth root calculation work.
If I have a number and need to find the nth root of base 2 of the number i am no further along with your solution.
i only know the answer is 2^1/n so how do i find n?
2017-06-20 09:22:53
Dennis Costello
Just to be pedantic, I'll point out that Maarten is almost correct. He said:
2^-1 for instance is 0.5 (2/2^1)
2^-3 is 0.125 (2/2^3)
When he meant
2^-1 for instance is 0.5 (1 / 2^1)
2^-3 is 0.125 (1 / 2^3)
2016-06-30 17:20:39
Maarten Daams
You can even use negative exponents.
2^-1 for instance is 0.5 (2/2^1)
2^-3 is 0.125 (2/2^3)
etc.
And so on.
Of course fractional negative exponents work also, but that is more complicated
2016-06-11 06:08:43
Polarisking
The POWER function also works here,
POWER(B7,1/5)
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