Inspired by Marc Renault's use of the second graphics window for zooming. See his calculus applets at[br][url]http://webspace.ship.edu/msrenault/GeoGebraCalculus/GeoGebraCalculusApplets.html[/url].[br][br]This sketch zooms in on the tangent at a point, or just at a point on a graph.[br][br]The left window controls the function graphed and the point on that curve. The right window controls the scale of the zoom.[br][br]EDIT: Jen Silverman convinced me that it was important to keep the zoom window 1:1, so I fixed that!

More GeoGebra at [url]mathhombre.blogspot.com[/url].