Polar Coordinates

Till this point we've dealt completely with the Cartesian (or Rectangular, or x-y) coordinate system.  Though, as we will see, this is not all time the easiest coordinate system to work in.  Thus, in this section we will start looking at the polar coordinate system.

 Coordinate systems are actually nothing much more than a way to describe a point in space.  For example in the Cartesian coordinate system at point is specified the coordinates (x,y) and we use this to describe the point by starting at the origin and after that moving x units horizontally followed by y units vertically.  This is illustrated in the diagram below.

Though, this is not the only way to define a point in two dimensional spaces.  In place of moving vertically and horizontally from the origin to obtain to the point we could in place of go straight out of the origin till we hit the point and then ascertain the angle this line makes with the positive x-axis.  We could then make use of the distance of point from the origin and the amount or value we required to rotate from the positive x-axis as the coordinates of the point.  This is illustrated in the diagram below.

Coordinates in this form are called polar coordinates.