Essential revision or learning for a wealth of disciplines like architecture, physics, engineering or design. Understanding the qualities of circles, lines and cones together with a thorough explanation of vectors, provide an excellent foundation to further study.

# Polar co-ordinates

The (x, y) co-ordinates of a point in the plane are called its Cartesian co-ordinates. But there is another way to specify the position of a point, and that is to use polar co-ordinates. Conversion from Cartesian co-ordinates to polar co-ordinates, and back again, is explained. Video tutorial 37 mins.