Re: Re: Reduce in Ver 6

*To*: mathgroup at smc.vnet.net*Subject*: [mg85558] Re: [mg85502] Re: Reduce in Ver 6*From*: Bob Hanlon <hanlonr at cox.net>*Date*: Wed, 13 Feb 2008 07:25:21 -0500 (EST)*Reply-to*: hanlonr at cox.net

Another approach is to use ReplaceRepeated when using the rules. equ = {a + b + c == 3, a^2 + b^2 + c^2 < 10, a^3 + b^3 + c^3 == 15, a^4 + b^4 + c^4 == 35}; sol = {ToRules[Reduce[equ, {a, b, c}]]}; a^5 + b^5 + c^5 //. sol // Simplify {83,83,83,83,83,83} Bob Hanlon ---- Dana DeLouis <dana.del at gmail.com> wrote: > > Use the Backsubstitution -> True setting for Reduce[] > > Darn! Yep! Right there in help under Reduce. > Thank you very much. I think I've been confusing this with the > "VerifySolutions" option under Solve. I now understand my mistake. Can't > believe I've missed this all this time. > Thanks again. > > equ = {a + b + c == 3, a^2 + b^2 + c^2 < 10, > a^3 + b^3 + c^3 == 15, a^4 + b^4 + c^4 == 35}; > > sol = {ToRules[Reduce[equ, {a, b, c}, > Backsubstitution -> True]]}; > > Simplify[a^5 + b^5 + c^5 /. sol] > {83, 83, 83, 83, 83, 83} > > -- > Dana DeLouis > > <snip> > > >> I use Reduce, but 'c is returned as a function of a & b. > >> What I would like is for c to replace a & b with the appropriate values. > >> > >> r = {ToRules[Reduce[equ, {a, b, c}]]} > >> > >> {{a -> 1, b -> 1 - Sqrt[2], c -> 3 - a - b}, > > > > Use the Backsubstitution -> True setting for Reduce[] > > > > Szabolcs > > > > >