Abscissa

Abscissa is the horizontal coordinate of a point in a Cartesian coordinate system. The term is used when measuring in the horizontal axis of a two-dimensional graph. Typically the coordinates of any point say point “P” are represented by the coordinate

On the graph below we can see the abscissa being represented as the horizontal distance to the vertical axis or y-axis.

Above abscissa or the x-coordinate is the first coordinate.

Sign of Abscissa

Here is a review of how the sign changes with the abscissa as you move around in the coordinate system.