Re: Demostration
- To: mathgroup at smc.vnet.net
- Subject: [mg70446] Re: Demostration
- From: Peter Pein <petsie at dordos.net>
- Date: Mon, 16 Oct 2006 02:36:17 -0400 (EDT)
- References: <egsdu4$cp1$1@smc.vnet.net>
Erickson Paul-CPTP18 schrieb:
> I guess this doesn't 'prove', but perhaps demonstrates:
>
>
> Select[ Range[-100000,200000], IntegerQ[Sqrt[#^3+9]] &]
>
> {-2,0,3,6,40}
>
> There are 5 x values within a reasonable range. The ten (fine pairs) are
> +/- due to the Sqrt for y.
>
>
> You might choice a smaller range in order for faster execution ;-)
You don't need to test for any integer x < -2, for example ;-)
>
>
>
>
> -----Original Message-----
> From: Miguel [mailto:mibelair at hotmail.com]
To: mathgroup at smc.vnet.net
> Subject: [mg70446] Demostration
>
> How canI to demostrate than the equation y^2=x^3+9 has 10 integer
> solutions?
>
>