Definition

1. Noun:
   • The x-coordinate in a two-dimensional Cartesian coordinate system: The abscissa is the horizontal coordinate of a point, representing its distance from the vertical (y-) axis, measured parallel to the horizontal (x-) axis. It is the first number in an ordered pair (x, y).

Usage

• The abscissa is used in mathematics, particularly in geometry, algebra, and graphing, to specify the horizontal position of a point on a plane.
• It is always paired with an ordinate (the y-coordinate) to define a point's exact location.

Examples

• Noun:
  • In the point (5, 3), the number 5 is the abscissa.
  • To plot the graph, you must first determine the abscissa for each data point.
  • The abscissa of the point where the line crosses the x-axis is zero.

Advanced Usage

• "Abscissa of convergence": In mathematical analysis, this refers to a specific value on the real axis related to the convergence of a Dirichlet series.
  • The abscissa of convergence determines where the series begins to converge.

Variants and Related Words

• Abscissae (n): The plural form of abscissa, often used in formal or technical writing.
  • The graph shows the abscissae of all intersection points.

Synonyms

• x-coordinate: The most direct synonym, specifying the coordinate on the horizontal axis.
• Horizontal coordinate: A descriptive synonym emphasizing the axis.

Antonyms

• Ordinate: Refers specifically to the y-coordinate or the vertical coordinate of a point.
• y-coordinate: The coordinate on the vertical axis.

Noun

1. the value of a coordinate on the horizontal axis