# Re: r28523 - docs/Perl6/Spec/S32-setting-library

```Jan Ingvoldstad wrote:
> On Thu, Oct 1, 2009 at 10:15 PM, Moritz Lenz <mor...@faui2k3.org> wrote:
>>
>>
>> What's the 0th root of a number, then?
>> It would be a number \$y for which \$y ** 0 == \$x, which can only be
>> fulfilled for \$x == 1. So in the general cases the answer to the
>> question root(\$x, 0) is nonsense, which is best mapped to NaN.
>>
>
> That doesn't make sense. The answer is 1, not NaN.
>
> Think about it for a while: mathematically speaking, we would expect the 0th
> root of a number to be 1.```
```
Excuse me?

given a number \$x, roots(\$x, \$n) returns a List (mathematically speaking
a Set) of numbers \$y, for which \$y**\$n == \$x holds true.

If roots(3, 0) returned 1, then 1**0 == 1, which is not 3. It's bettter
to return NaN to indicate an impossible operation, rather than to return
an ordinary number which is a wrong result.

It is not obvious to me why 1 or in fact any defined number at all would
be a mathematically sensible result - care to elaborate?

Cheers,
Moritz
```