x() - The x-coordinate of a point

GeoGebra is currently 2D. So points are ordered pairs of real numbers.
Example: A=(-3,6.21) means x(A)= -3 .
The first number is the horizontal x-coordinate and the second number is the vertical y-coordinate.

In the Algebra View (at left), click and leave your mouse on a to see the definition Number a: x(A).
In the Graphics View (at right), click and drag point A and notice how the value of a changes.

Note: This is a pre-defined function. Pre-defined functions need to be entered using parentheses. You must not put a space between the function name and the parentheses.  Pre-defined functions are case sensitive. If you type X(A) you will get: GeoGebra Error, Invalid Input,... . Use x(A).