..
  Copyright 1988-2021 Free Software Foundation, Inc.
  This is part of the GCC manual.
  For copying conditions, see the GPL license file

.. _acosd:

ACOSD --- Arccosine function, degrees
*************************************

.. index:: ACOSD

.. index:: DACOSD

.. index:: trigonometric function, cosine, inverse, degrees

.. index:: cosine, inverse, degrees

.. function:: ACOSD(X)

  ``ACOSD(X)`` computes the arccosine of :samp:`{X}` in degrees (inverse of
  ``COSD(X)`` ).

  :param X:
    The type shall either be ``REAL`` with a magnitude that is
    less than or equal to one - or the type shall be ``COMPLEX``.

  :return:
    The return value is of the same type and kind as :samp:`{X}`.
    The real part of the result is in degrees and lies in the range
    0 \leq \Re \acos(x) \leq 180.

  :samp:`{Standard}:`
    GNU extension, enabled with :option:`-fdec-math`

  :samp:`{Class}:`
    Elemental function

  :samp:`{Syntax}:`

  .. code-block:: fortran

    RESULT = ACOSD(X)

  :samp:`{Example}:`

    .. code-block:: fortran

      program test_acosd
        real(8) :: x = 0.866_8
        x = acosd(x)
      end program test_acosd

  :samp:`{Specific names}:`
    =============  =============  ===========  =============
    Name           Argument       Return type  Standard
    =============  =============  ===========  =============
    ``ACOSD(X)``   ``REAL(4) X``  ``REAL(4)``  GNU extension
    ``DACOSD(X)``  ``REAL(8) X``  ``REAL(8)``  GNU extension
    =============  =============  ===========  =============

  :samp:`{See also}:`
    Inverse function: 
    COSD 
    Radians function: 
    ACOS