An Introduction to Curve Sketching - Mark Holland

29th March 2003

You will be aware of the idea of cartesian co-ordinates, that is, describing a point in the plane by specifying its distance from the \(x\) and \(y\)-axes. Every point can also be referred to, however, by its polar co-ordinates, by specifying the length of the line from your point to the origin, and the angle this line makes with the positive \(x\)-axis. This presentation looks at polar co-ordinates, and how equations using them can describe different curves. It also looks at curves traced out by a point on a disc rolling on a surface, then on and within another disc.