Re: Mathematica max, min

• To: mathgroup at smc.vnet.net
• Subject: [mg55507] Re: [mg55495] Mathematica max, min
• From: Bob Hanlon <hanlonr at cox.net>
• Date: Sun, 27 Mar 2005 02:42:39 -0500 (EST)
• Sender: owner-wri-mathgroup at wolfram.com

```f[x_,y_] := 3*x^4+3*x^2*y-y^3;

(mmpts={x,y,f[x,y]}/.
(D[f[x,y],#]&/@{x,y})==0],
{x,y}]])

{{-(1/2), -(1/2), -(1/16)}, {0, 0, 0}, {1/2, -(1/2), -(1/16)}}

Show[{Plot3D[f[x,y],
{x,-3/4,3/4},{y,-3/4,1/4},
PlotRange->All,
DisplayFunction->Identity],
Graphics3D[{AbsolutePointSize[6],Red,
Point/@mmpts}]},
DisplayFunction->\$DisplayFunction];

It is somewhat easier to see if you zoom-in on each point

Show[{Plot3D[f[x,y],
{x,#[[1]]-0.05,#[[1]]+0.05},
{y,#[[2]]-0.05,#[[2]]+0.05},
PlotRange->All,
DisplayFunction->Identity],
Graphics3D[{AbsolutePointSize[6],Red,
Point[#]}]},
DisplayFunction->\$DisplayFunction]&/@
mmpts;

Bob Hanlon

>
> From: diasydias <e at e.com>
To: mathgroup at smc.vnet.net
> Date: 2005/03/26 Sat AM 02:39:25 EST
> To: mathgroup at smc.vnet.net
> Subject: [mg55507] [mg55495] Mathematica max, min
>
> Hi,
> Could someone pls help me how to input the following max, min problem
into Mathematica?
>
> z = 3x^4 + 3xÂ²y -y^3
>
> Thanks
>
>

```

• Prev by Date: Re: 3D Plots: Specifying GridLine spacing for FaceGrids
• Next by Date: Re: numerical solutions to two non algebraic equations.
• Previous by thread: Mathematica max, min
• Next by thread: Re: Mathematica max, min