In article <[EMAIL PROTECTED]>, "Terry Reedy" <[EMAIL PROTECTED]> wrote:
> "Lou Pecora" <[EMAIL PROTECTED]> wrote in message > news:[EMAIL PROTECTED] > | In article <[EMAIL PROTECTED]>, > | "Terry Reedy" <[EMAIL PROTECTED]> wrote: > | > | > "Luis Zarrabeitia" <[EMAIL PROTECTED]> wrote in message > | > news:[EMAIL PROTECTED] > | > | Btw, there seems to be a math problem in python with > exponentiation... > | > | >>> 0**0 > | > | 1 > | > | That 0^0 should be a nan or exception, I guess, but not 1. > | > > | > a**b is 1 multiplied by a, b times. 1 multiplied by 0 no times is 1. > | > But there are unenlighted people who agree with you ;-) > | > Wikipedia has a discussion of this. > | > > | > tjr > | > | I like that argument better. But... > | > | I've also heard the very similar a**b is a multiplied by a b-1 times. > > Me too, in school, but *that* definition is incomplete: it excludes b=0 and > hence a**0 for all a. It was the best people could do before 0 was known. > But 0 was introduced to Europe just over 800 years ago ;-) [cut some interesting examples] Yes, I was also thinking about the b=0 case and then the case when b<0. If you solve the b<0 case, you solve the b=0 case for a !=0. Define a**b= a multiplied by 1/a |b-1| times when b<0. Then for b=0 we get a*(1/a)=1. Of course, I can avoid all this mathematical dancing around by using some of the other simpler definitions like the original one. :-) -- -- Lou Pecora -- http://mail.python.org/mailman/listinfo/python-list
