(-1)^(1/7) = NaN

[Former user]

Some fractional powers do not yield the desired result for negative values. For example:

(-1)^(1/3)=-1 (-1)^(1/5)=-1 (-1)^(1/7)=NaN

Some other examples: (-1)^(1/49)=NaN, (-1)^(1/63)=NaN.

[Alister Hood]

Looks like a duplicate of #1042