Re: On Reduce
- To: mathgroup at smc.vnet.net
- Subject: [mg72020] Re: [mg72011] On Reduce
- From: Bob Hanlon <hanlonr at cox.net>
- Date: Sat, 9 Dec 2006 06:09:26 -0500 (EST)
- Reply-to: hanlonr at cox.net
BInv={{1/4, 1/4, 0},
{-1/2, 1/2, 0},
{3/4, -5/4, 1}};
B=Inverse[BInv];
b={4 + \[Delta], 8, 10};
BInv.b // Simplify;
ineq=Reduce[Thread[% >= 0], \[Delta]]/.
{\[Delta] -> b1-4} // Simplify
0 <= b1 <= 8
{First@ineq, Last@ineq}
{0,8}
Cases[ineq, _?NumericQ]
{0,8}
Bob Hanlon
---- Virgil Stokes <vs at it.uu.se> wrote:
> I have the following small piece of Mathematica code that works fine for
> my purposes.
>
> BInv = {{ 1/4, 1/4, 0},
> {-1/2, 1/2, 0},
> { 3/4, -5/4, 1}}
> B = Inverse[BInv]
> b = {4 + \[Delta], 8, 10};
> BInv.b // FullSimplify
> Reduce[{%[[1]] >= 0, %[[2]] >= 0, %[[3]] >= 0}, {\[Delta]}]
> % /. {\[Delta] -> b1 - 4} // FullSimplify
>
> which gives
>
> 0 <= b1 <= 8
>
> which is of course correct. But, how can I use (access) the values 0 and 8?
> That is, I would like to now use these values in some expressions that
> would follow this.
>
> Thanks,
> V. Stokes
>