Definition:Cartesian Coordinate System/X Coordinate

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Definition

Consider a Cartesian coordinate system $C$ with an $x$-axis.

Let a point $Q$ be positioned in $C$.


Let $x$ be the length of the line segment from the origin $O$ to the foot of the perpendicular from $Q$ to the $x$-axis.

Then $x$ is known as the $x$ coordinate.

If $Q$ is in the positive direction along the real number line that is the $x$-axis, then $x$ is positive.

If $Q$ is in the negative direction along the real number line that is the $x$-axis, then $x$ is negative.


Also known as

An archaic term for the $x$ coordinate which is sometimes seen is abscissa.


Also see


Sources