
Re: visualizing a maximum in the intersection between
Posted:
Jun 11, 2013 2:24 AM


Le 08/06/2013 08:34, dusko.cakara@gmail.com a =C3=A9crit : > Hello, > can somebody please help: > I want to visualize that for x+y=1, maximum x*y occurs when y=0.5 and x=0.5. > > Graphically, this can be visualized as the maximum of the projection curve of the x+y=1 line in the xy plane, at the x*y surface. Equivalently, we can look for the maximum in the intersection curve between the surface x*y and the surface peripendicular to the xy plane with the base x+y==1. > > Can I plot this in a simple manner? > > Thanks in advance! > Dusko > > Here is one easy way.
Plot[x*(1  x), {x, 0, 1}]
This gives a plot of all the points x*y satisfying the condition x+y=1 (or y=(x1)). The maximum of .25 occurs when x=y=1x
Leigh

