Tangent plane and normal line to a surface

This applet illustrates the computation of the normal line and the tangent plane to a surface at a point .
  1. Select the point where to compute the normal line and the tangent plane to the graph of using the sliders.
  2. Check the box Normal line to plot the normal line to the graph of at the point , and to show its equation.
  3. Check the box Tangent plane to plot the tangent plane to the graph of at the point , and to show its equation.
  4. Enter a new function and repeat the previous steps.
Get more info about the normal line and the tangent plane to a surface at http://aprendeconalf.es.
– Alfredo Sánchez Alberca

Information: Tangent plane and normal line to a surface