Punjabi Mathematician wrote:

What's the mathematical formula behind the Excel Power Function?

POWER(number, power)

How do you determine the value of (2)^(0.5) or POWER(2, 0.5)

Are you asking how one calculates roots?

I don't know the formula Excel uses, but Rosetta Code has a page covering
this topic:

http://rosettacode.org/wiki/Nth_root

Wikipedia also has a page discussing it:

https://wikipedia.org/wiki/Nth_root_algorithm

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