HP Fortran Programmer's Reference (September 2007)

Intrinsic procedures
Intrinsic procedure specifications
Chapter 11 517
Result type/
type parameters
Same as X.
Result value
The result has a value equal to a processor-dependent approximation to arccos(X), expressed
in degrees. It lies in the range 0 <= ACOSD(X) <= 180.
Specific forms
DACOSD, QACOSD.
ACOSH(X)
Description
Hyperbolic arccosine of radians.
Class
Elemental nonstandard function.
Argument
X must be of type real with a value X >= 1.
Result type/
type parameters
Same as X.
Result value
The result has a value equal to a processor-dependent approximation to the hyperbolic
arccosine of X. It lies in the range 0 <= ACOSH(X).
Specific forms
DACOSH, QACOSH.