Re: Re: Solve inconsistant actions?

*To*: mathgroup at smc.vnet.net*Subject*: [mg87257] Re: [mg87217] Re: Solve inconsistant actions?*From*: Bob Hanlon <hanlonr at cox.net>*Date*: Sat, 5 Apr 2008 04:25:51 -0500 (EST)*Reply-to*: hanlonr at cox.net

newrent = Table[125000 E^(r 14), {r, .01, .04, .005}]; The only case with a problem (its algorithms couldn't find a solution) is Solve[#/rate == 1894000, rate] & /@ newrent // Column {{rate->0.0759156}} {} {} {{rate->0.0936555}} {} {{rate->0.107729}} {{rate->0.115541}} I find that simplifying an expression can sometimes help. Solve[Simplify[#/rate == 1894000], rate] & /@ newrent // Column {{rate->0.0759156}} {{rate->0.0814201}} {{rate->0.0873238}} {{rate->0.0936555}} {{rate->0.100446}} {{rate->0.107729}} {{rate->0.115541}} This is equivalent to what you did with Solve[# == 1894000 rate, rate] & /@ newrent Alternatively, use only exact or only approximate numbers (as in one of your examples). Hence, either Solve[Simplify[#/rate == 1894000.], rate] & /@ newrent // Column or Solve[#/rate == 1894000, rate] & /@ Rationalize[newrent, 0] // N // Column And Reduce has more robust capabilities than Solve Bob Hanlon ---- mhicks <mhicks at san.rr.com> wrote: > Can someone enlighten me as to what discriminators Solve uses in > providing some solutions while disdaining others in the attached simple > code? > > Is it an operator or Mathematica bug? I am running 6.0.1 under win xp. > > > newrent = Table[125000 \[ExponentialE]^(r 14), {r, .01, .04, .005}] // N > > Table[Solve[newrent[[i]]/rate == 1894000 , rate], {i, 1, 7}] > > Table[Solve[newrent[[i]]/rate == 1894000. , rate], {i, 1, 7}] > > Table[Reduce[newrent[[i]]/rate == 1894000 , rate], {i, 1, 7}] > > Table[Solve[newrent[[i]] == 1894000 rate, rate], {i, 1, 7}] > > > Thanks for any help, > > Marlyn Hicks > > mhicks at san.rr.com > >