How to get nth root of a number in Ruby?

Question

For example

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x ** 3 # => 125

Knowing that the result of applying ** with an argument 3 to x is 125, how can I get the value of x? Is there some kind of built-in method for this? I have been looking at the Math module but didn't find anything similar.

Answer 1

Using ** with 1/3:

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125 ** (1.0/3)
# => 4.999999999999999

Answer 2

You could also try as below :

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irb(main):005:0> 125**(3**-1)
=> 5
irb(main):006:0> 125**(3**-1.0)
=> 4.999999999999999
irb(main):007:0>

update

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C:\Users >ruby -v
ruby 1.9.3p448 (2013-06-27) [i386-mingw32]