It is a horizontal line that is represented mainly in rectangular Cartesian coordinates and its mission is to mark the distance between the vertical axis and the center or any point. The abscissa axis, for its part, are taken as the set of horizontal coordinates of a Cartesian plane.
Its original mathematical scope is Cartesian geometry, developed between the seventeenth and eighteenth centuries, by the important philosopher René Descartes (1596-1650), however, it officially enters the area of analytic geometry, which arose starting from the Cartesian, this, is in charge of studying geometric figures, but from an algebraic point of view, that is, with mathematical analysis. Likewise, it is very present within differential and algebraic geometry, who study the coordinates in a similar way to those mentioned at the beginning.
The horizontal line, in a Cartesian coordinate, is represented with an X and the vertical with a Y (called the ordinate), they have to be perpendicular and coincide with each other. The point where they meet each other is known as the origin of coordinates. Its center is represented with the symbol "O", which is considered neutral, because, within the graph, a series of lines are established along all the lines, in which the positive and negative numbers are located, the first ones being to the right and the last ones to the left. Finally, there are three types of presenting coordinates: linear, plane and spatial, each one is characterized by having a certain number of axes, ranging from one to three, respectively.
