Analytical geometry was primarily conceived by the French philosopher René Descartes (1596-1650). With the aid of an axis system associated with a plane, it matches each point of the plane with an ordered pair and vice versa.

When the axes of these systems are perpendicular in origin, this correspondence determines an orthogonal Cartesian (or Cartesian plane) system.

Thus, there is a reciprocity between the study of geometry (point, line, circumference) and algebra (relations, equations, etc.), and it is possible to graph algebraic relations and express algebraically graphical representations. Observe the Cartesian plane in the four quadrants:

Examples:

**THE**(2, 4) belongs to the 1st quadrant (x_{THE}> 0 and y_{THE}> 0)**B**(-3, -5) belongs to the 3rd quadrant (x_{B}<0 and y_{B}< 0)

Note: By convention, the points located on the axes are not in any quadrant.

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