RE: How can solue the inequation system in mathematica

*To*: mathgroup at smc.vnet.net*Subject*: [mg34758] RE: [mg34728] How can solue the inequation system in mathematica*From*: "DrBob" <majort at cox-internet.com>*Date*: Wed, 5 Jun 2002 03:38:16 -0400 (EDT)*Reply-to*: <drbob at bigfoot.com>*Sender*: owner-wri-mathgroup at wolfram.com

Here's a little code and a plot to get you started: Needs["Graphics`InequalityGraphics`"] ineq = {2*x^3 + y^ +1 > 0, 5*x^2 - y^2 + 5 < 0}; eqns = {x, y /. #} & /@ Flatten[Solve[#, y] & /@ (ineq /. {Greater -> Equal, Less -> Equal})] xRange = {x, -10, 10}; yRange = {y, -20, 20}; Show[{ ParametricPlot[Evaluate[eqns], Evaluate[xRange], DisplayFunction -> Identity], InequalityPlot[ineq, Evaluate[xRange], Evaluate[yRange], DisplayFunction -> Identity]}, PlotRange -> {Rest[xRange], Rest[yRange]}, ImageSize -> 400, DisplayFunction -> $DisplayFunction] One issue you face is "What does a solution look like?" A picture? A dichotomy of the solution set? If the latter, you can find intersections of the equality curves and, based on those, state the solution set in y for each range of x values (or in x for each range of y values). Bobby Treat -----Original Message----- From: DrBob [mailto:majort at cox-internet.com] To: mathgroup at smc.vnet.net Subject: [mg34758] RE: [mg34728] How can solue the inequation system in mathematica Check out the InequalityGraphics package (Addons>Standard Packages>Graphics>InequalityGraphics in Help), and you can also try InequalityInstance in the Developer package. I think you'll have to figure it out yourself, with Mathematica's help. For instance, in the problem you've listed below, you can fix x and solve the corresponding equations for y, and figure out from that what range of y values are feasible for that x. You can do the similar thing fixing x and solving for y. You might even make it fairly automatic, as InequalityGraphics has done. Bobby -----Original Message----- From: MailPhys [mailto:physics.nsu at bdvn.vnd.net] To: mathgroup at smc.vnet.net Subject: [mg34758] [mg34728] How can solue the inequation system in mathematica Dear friends This my question. How can I solve the Inequation system in mathematica. I haven't seen any command for that for example 2*x^3 +y^ +1 >0 5*x^2 -y^2+5<0 If you know that , please point out to me Thank you