ACOSH intrinsic function
Standard: F77 F90 F95 F2003 F2008 Example program
＜Syntax＞
ACOSH ( X )
X : Real or Complex;
Result : Same type and kind as X.
＜Semantics＞
The value of the result is an approximation to the arc hyperbolic cosine of X. 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 greater than or equal to 1. If X is of type Complex, the imaginary part of the result is in radians, in the range 0.0≤AIMAG(ACOSH(X))≤π.