ordonate

Ordinate is a term used in Cartesian coordinate geometry to denote the y-coordinate of a point. In a two-dimensional plane, any point is written as (x, y), where x is the abscissa (horizontal distance from the origin) and y is the ordinate (vertical distance from the origin). The ordinate specifies the point’s vertical position relative to the x-axis and can be used to describe graphs of functions as y = f(x). For a given x value, the corresponding ordinate is the value of the function at that x.

In three dimensions, a point is written as (x, y, z). Here, the second component y remains the ordinate, while z is the third coordinate. In higher dimensions, the concept generalizes in the same way, with the second component often referred to as the ordinate in 3D contexts.

Plotting conventions typically place ordinates along the vertical axis and abscissas along the horizontal axis. The distinction between abbscissa and ordinate helps differentiate horizontal and vertical components in graphs, algebraic equations, and data visualization.

Language notes: in other languages, equivalent terms exist, such as ordonnée in French and ordinata in Italian. In English usage, the standard term is ordinate, or more explicitly the y-coordinate.

Examples: the point (3, 5) has abscissa 3 and ordinate 5. For the line defined by y = 2x, the ordinate at any x-value is twice the corresponding abscissa, illustrating the relationship between the two coordinates on a graph.