[issue27761] Private _nth_root function loses accuracy

[Mark Dickinson]

Mark Dickinson added the comment:

> And it's still the case that I haven't found a case where its result isn't correctly rounded.

Here's one: :-)

>>> rootn(1 + 2**-52, 2)
1.0000000000000002

The correctly rounded result would be 1.0.

----------

_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue27761>
_______________________________________