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 >