I haven't studied physics since 1989 so forgive me if I don't follow the magnet model.

You write:

> I would need to include some sort of parameter in the equation to get the maximum

As a result of my ignorance, I don't understand what that means either. However:

If your g is positive and if you *know* that the maximum you're looking for is interior (as opposed to at a corner like g=0), then yes your equations must be modified so that an interior maximum be located in a region of positive g.

I can't even begin to make constructive suggestions about that unfortunately.

I haven't studied physics since 1989 so forgive me if I don't follow the magnet model.

You write:

> I would need to include some sort of parameter in the equation to get the maximum

As a result of my ignorance, I don't understand what that means either. However:

If your g is positive and if you *know* that the maximum you're looking for is interior (as opposed to at a corner like g=0), then yes your equations must be modified so that an interior maximum be located in a region of positive g.

I can't even begin to make constructive suggestions about that unfortunately.

right you are Doug , besides amocella's track record suggests that he/she doesn't keep track of his/her threads!

right you are Doug , besides amocella's track record suggests that he/she doesn't keep track of his/her threads!

thanks acer,
 

fsolve( tt->zerovalue(tt)-8, 195..200);

                             198.8831747

fsolve( 'zerovalue'(tt)-8, tt=195..200);

                             198.8831747

thanks acer,
 

fsolve( tt->zerovalue(tt)-8, 195..200);

                             198.8831747

fsolve( 'zerovalue'(tt)-8, tt=195..200);

                             198.8831747

very nice, very useful tips for me too.

I got the following error message in Maple 13.01/Classic:

fsolve(zerovalue - 8, 195 .. 200);
Error, (in fsolve) Can't handle expressions with typed procedures

very nice, very useful tips for me too.

I got the following error message in Maple 13.01/Classic:

fsolve(zerovalue - 8, 195 .. 200);
Error, (in fsolve) Can't handle expressions with typed procedures

and what is the probability distribution/density for x? a non-stochastic random variable is after all a (degenerate) stochastic variable...

P.S. in introductory econometrics it is often assumed that x is non-stochastic.

It isn't obvious from the graph that there is a finite maximum, as opposed to a divergence. From the picture I get, it looks like g is negative. It also looks like there's a "twin peak", that's two symmetric maxima for h positive and negative. But it could be an artefact caused by the imprecision of the calculations. I'm sure someone will offer more useful suggestions than mine.

p := plot3d(HorBx, g=-2e-2..1e-2, h=-1.1e-2..1.1e-2):
display(p, axes=box, style=patchcontour, orientation=[-90,90]);
display(p, axes=box, style=patchcontour, orientation=[-180,90]);

It isn't obvious from the graph that there is a finite maximum, as opposed to a divergence. From the picture I get, it looks like g is negative. It also looks like there's a "twin peak", that's two symmetric maxima for h positive and negative. But it could be an artefact caused by the imprecision of the calculations. I'm sure someone will offer more useful suggestions than mine.

p := plot3d(HorBx, g=-2e-2..1e-2, h=-1.1e-2..1.1e-2):
display(p, axes=box, style=patchcontour, orientation=[-90,90]);
display(p, axes=box, style=patchcontour, orientation=[-180,90]);

if x is non-stochastic, then you don't need to worry about the b power, just raise your data to the power b and consider y = a*X+c...

helps find intersections, for instance (from the help menu):

with(geom3d):

plane(p1,4*x+4*y-5*z=12,[x,y,z]):
plane(p2,8*x+12*y-13*z=32,[x,y,z]):
intersection(l,p1,p2):
detail(l);

helps find intersections, for instance (from the help menu):

with(geom3d):

plane(p1,4*x+4*y-5*z=12,[x,y,z]):
plane(p2,8*x+12*y-13*z=32,[x,y,z]):
intersection(l,p1,p2):
detail(l);

eq1 := 5*x^4*z^3*y + x^3*y^5*z + 10*exp(x*y*z-2) -98 ;
eq2 := tan(x*y*z-2) + ln(3*x + y + z -7) ;
implicitplot3d({eq1,eq2}, x=0..10, y=0..10, z=0..10, axes=box);