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Topic: Multiplication by 0: non-zero in versions 8 and 9
Replies: 2   Last Post: Jun 16, 2013 5:14 AM

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 Bob Hanlon Posts: 906 Registered: 10/29/11
Re: Multiplication by 0: non-zero in versions 8 and 9
Posted: Jun 16, 2013 5:14 AM

Use of inexact numbers produces inexact results (which can be handled with
Rationalize or Chop). Use of exact numbers produes exact results.

Times[1.23 + I 2.45, 0] // Rationalize

0

Times[1.23 + I 2.45, 0] // Chop

0

Times[123/100 + I 245/100, 0]

0

Times[1.23 + I 2.45 // Rationalize, 0]

0

Bob Hanlon

On Sat, Jun 15, 2013 at 4:23 AM, Sotirios Bonanos <sbonano@inp.demokritos.gr
> wrote:

> Hello ,
>
> I have noticed that in all Mathematica versions <8, multiplying a real or
> complex number by the integer 0 gives 0, but in versions 8 and 9
>
> Times[0, 0.567] gives 0.
>
> and
>
> Times[1.23 + I 2.45, 0] gives 0. + 0. I
>
> I don't know what prompted this change but it is definitely wrong: the
> zero property of multiplication holds for real and complex numbers also
> (see https://en.wikipedia.org/wiki/Multiplication#Properties) .
>
> Sotirios Bonanos
> http://www.inp.demokritos.gr/~sbonano/
>
>
>

Date Subject Author
6/16/13 Murray Eisenberg
6/16/13 Bob Hanlon