show gradient vectors orthogonal to level curves



On Qua, 2009-10-21 at 18:31 +0100, Jaime Villate wrote:
> I am trying to demonstrate that gradient vectors are orthogonal to
> > contour lines.

> Please try the following:...

You can also get the plot you want with the following command:

  ploteq(y^2-x^2,[x,y],[x,-3,3],[y,-3,3],[vectors,"blue"]);

and then click on a few points.

Jaime