Re: Simplification

• To: mathgroup at smc.vnet.net
• Subject: [mg75453] Re: [mg75431] Simplification
• From: "Richard Palmer" <rhpalmer at gmail.com>
• Date: Tue, 1 May 2007 03:25:43 -0400 (EDT)
• References: <200704300740.DAA22559@smc.vnet.net>

```Huh?

Try ans = Product[Cos[(2^j*Pi)/1023], {j, 0, 9}]/Product[Cos[(2^j*Pi)/
1025], {j, 0, 9}]
N[ans]

I'm not sure what your trouble was.  I don't think Mathematica is having any
problem here.

Regards,  Richard Palmer

On 4/30/07, dimitris <dimmechan at yahoo.com> wrote:
> This appeared in another forum.
>
> (Converting to Mathematica InputForm.)
>
> In[2]:=
> oo = Product[Cos[(2^j*Pi)/1023], {j, 0, 9}]/Product[Cos[(2^j*Pi)/
> 1025], {j, 0, 9}];
>
> The expression can be simplified to -1.
>
> Indeed, adopted by someone's reply, in another CAS, we simply have
>
> Product(cos(Pi*2^j/1023), j= 0..9)/ Product(cos(Pi*2^j/1025), j=
> 0..9):
>  p:=value(%):
>  convert(p, sin):
>  simplify(%);
>                                                    -1
>
> However, no matter what I tried I was not able to succeed in
> simplifying above expression
> to -1 with Mathematica, in reasonable time. Futhermore, even the much
> more simpler of
> showing oo==-1 didn't work.
>
> So I would really appreciate if someone pointing me out:
> 1) A way to show (in Mathematica!) that oo is simplified to -1
> 2) That the equality oo==-1 (or oo-1==0 alternatively) can be
> simplified
> to True.
>
> Any ideas?
>
> BTW, I found the function convert of the other CAS, very useful.
> Has anyone implementated a similar function in Mathematica?
> (I ain't aware of a Mathematica built-in function, similar to convert
> from the other CAS.)
>
> Dimitris
>
>
>

--
Richard Palmer
Cell 508 982-7266

```

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