In details

Ordered Pairs


Often, to locate a point on a plane, we use two rational numbers in a certain order. We call these numbers ordered pair. Examples:


Like this:

We indicate by (x, y) the ordered pair formed by the elements x and y, Where x is the 1st element and y is the 2nd element.

Comments:

1) In general, being x and y any two rational numbers we have: . Examples:

2) Two ordered pairs (x, y) and (r, s) are equal only if x = r and y = s.

Graphical representation of an ordered pair

We can represent a pair ordered by a point in a plane. This point is called the Image of the ordered pair.

Next: Cartesian Coordinates