ACOS intrinsic function
Standard: F77 F90 F95 F2003 F2008 Example program
<Syntax>
ACOS ( X )
X : Real or Complex;
Result : Same type and kind as X.
<Semantics>
The value of the result is an approximation to the arc cosine of X, in radians. Like many intrinsic functions, this is elemental; the result has the same shape as X, with the operation being applied elementwise.
If X is of type Real, it must be in the range −1≤X≤+1, and the result will be in the range 0.0≤ACOS(X)≤π. If X is of type Complex, the real part of the result is in radians, in the range 0.0≤REAL(ACOS(X))≤π.