AS/A2 Pure 4 Pure 6

P5 Topic 1: Coordinate Systems
The circle
The circle is an example of a conic section. The illustration comes from Jill Britton. In the display below use your mouse to change the values of a, b or r. The graph displayed is a circle. It is described by the Cartesian equation:

Summary Note that the circle will only appear circular if the scales on the axes are the same. If they are not, click Equalize Axes. Based on free Java applets from JavaMath