# The abscissa of a point or vector in the plane: abscissa

### 13.13.2 The abscissa of a point or vector in the plane: abscissa

See Section 14.12.1 for abscissas in three-dimensional geometry.

The abscissa command finds the abscissa (x-coordinate) of a point.

- abscissa takes one argument:
  P, a point.
- abscissa(P) returns the abscissa of P.

#### Examples.

- Input:
  abscissa(point(1 + 2*i))
  Output:

  1

- Input:
  abscissa(point(i) - point(1 + 2*i))
  Output:

  −1

- Input:
  abscissa(1 + 2*i)
  Output:

  1

- Input:
  abscissa([1,2])
  Output:

  1