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 [math]P[/math].[br][br][list=1][*]Select the point [math]P=\left(x_0,y_0\right)[/math]where to compute the normal line and the tangent plane to the graph of [math]f[/math] using the sliders. [/*][*]Check the box Normal line to plot the normal line to the graph of [math]f[/math] at the point [math]P[/math], and to show its equation.[/*][*]Check the box Tangent plane to plot the tangent plane to the graph of [math]f[/math] at the point [math]P[/math], and to show its equation.[/*][*]Enter a new function and repeat the previous steps.[/*][/list]
Get more info about the normal line and the tangent plane to a surface at [url=http://aprendeconalf.es/calculus/manual/derivatives-n-variables.html#Tangentplaneandnormallinetoasurface]http://aprendeconalf.es[/url].

Information: Tangent plane and normal line to a surface