Find the Nth root in R

Question

How do we find the Nth root in R?

4^2 = sqrt(16)

But what is the code snippet for the opposite transformation of;

4^7 = ???

Answer 1

Simple

sqrt(4) == 4^(1/2)
# 7th root of 4
4^(1/7)

In calculus, roots are treated as special cases of exponentiation, where the exponent is a fraction:

https://en.wikipedia.org/wiki/Nth_root#Definition_and_notation

Answer 2

You should probably NOT use x^(1/n). It works perfectly well with nonnegative numbers, but if you tried

(-4)^(1/7)

you would get NaN. A better way is with nthroot.

> library(pracma)
> nthroot(-4, 7)
[1] 1.219