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Topic: ----------- math reference
Replies: 3   Last Post: Aug 10, 2011 6:29 PM

 Messages: [ Previous | Next ]
 Tim Little Posts: 1,793 Registered: 2/7/09
Re: ----------- math reference
Posted: Aug 8, 2011 10:18 PM

On 2011-08-08, Deep <deepkdeb@yahoo.com> wrote:
> I would appreciate it very much if someone can refer me to an
> appropriate reference where following statement is justified.
>
> Statement: Every integer N that is not 2mod4 can be expressed as the
> difference of two squares.

No reference necessary.

For odd numbers: 2n+1 = (n+1)^2 - n^2.
For numbers divisible by 4: 4n = (n+1)^2 - (n-1)^2.

They may also have other representations, but these suffice to justify
the statement.

--
Tim

Date Subject Author
8/8/11 Deep Deb
8/8/11 Tim Little
8/10/11 Ulrich D i e z
8/10/11 Ulrich D i e z