The argument *x* of the arc secant relation is a real number between \(-\infty\) and \(+\infty\).

The relation defined by *y* = arcsec(*x*) is not a function.

### Notation

The symbol used for the arc secant of a number *x* is “arcsec(*x*)” which is generally read as “arc secant of *x*.”

### Examples

In the sexagesimal system of measuring angles, we have:

arcsec(2) = 60

arcsec(2) = 360n ± 60 where n is an integer.

- arcsec(2) = 60
- arcsec(2) = 360
*n*± 60 where*n*n is an integer.

Because sec(60°) = 2, arcsec(2) = 60.

It is the same for all angles from “60° ± 360°.”