Three sliders, a, b, and α adjust the general equation of an ellipse. Sliders h and k transform the equation horizontally and vertically. a and b set the major and minor axis and α allows the ellipse to rotate.
What are the setting ranges for a, b, and α to show a vertical ellipse? A horizontal ellipse? What settings changes are needed to set the rotation of the ellipse to 45°, 120°, 215°, or 330°? What settings create a circle? What settings create a point? Source: [url=http://www.maa.org/external_archive/joma/Volume8/Kalman/General.html]General Equation of Ellipse[/url]