ACOS — Arccosine function

ACOS(X)

ACOS(X) computes the arccosine of X (inverse of COS(X)).

Parameters

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

Returns

The return value is of the same type and kind as X. The real part of the result is in radians and lies in the range 0 leq Re acos(x) leq pi.

Standard:

Fortran 77 and later, for a complex argument Fortran 2008 or later

Class:

Elemental function

Syntax:

RESULT = ACOS(X)

Example:

program test_acos
  real(8) :: x = 0.866_8
  x = acos(x)
end program test_acos

Specific names:

Name	Argument	Return type	Standard
ACOS(X)	REAL(4) X	REAL(4)	Fortran 77 and later
DACOS(X)	REAL(8) X	REAL(8)	Fortran 77 and later

See also:

Inverse function: COS Degrees function: ACOSD