The ACOS function returns the trigonometric arccosine of a real number, in radians.

## Syntax

ACOS (x)

x is an INTENT(IN) scalar or array of type REAL and must be within the range
*i* ≤ 1

A REAL representation, expressed in radians, of the arccosine of x.

## Example

real :: x=.5 write(*,*) acos(x) ! writes 1.0471975