From: Fleck Jean-Julien Date: 2009-12-19T02:02:41+09:00 Subject: Re: Math errors > That is WRONG, you cannot do that. Well, I never said that you should do that, I just explained how Ruby interpreted it... > That only works for odd roots of negative numbers. > The even root of negative numbers are imaginary. > > -27**3**-1 => -3 **correct > -27**2**-1 => -5.19615242270663 **WRONG, its 5.196152i Sure. That's quite a hint why ** does not accept a negative number with a non integer exponent. To take into account all the special cases, you should first see if your exponent is a rational and in that case, see if the denominator is odd (after all due simplifications of course). In this case (and only this case), you could try to decipher a root for this negative number. Cheers, -- JJ Fleck PCSI1 Lycée Kléber