HP 3000 Manuals

Compiler Library/XL Reference Manual

DCOS (or DCOS') 

DCOS calculates the cosine of a longreal number in radians.

Declaration 

        FUNCTION DCOS(VAR x:LONGREAL):LONGREAL; EXTERNAL;

Accuracy 


Attributes 

Parameter:                A longreal number in radians.

Result:                   A representable longreal number in the range
                          [-1.0, 1.0].  See Chapter 1 for details on the
                          internal representation of longreal numbers.

HP FORTRAN 77/XL:         Intrinsic function:  Y=DCOS(X).

Error:                    If the argument is a NaN or an Infinity, there
                          are two cases.  If the INVALID trap is enabled,
                          the message "DCOS(X): X=NaN OR INFINITY"
                          occurs.  Otherwise, the INVALID flag is set.
                          In either case, a quiet NaN is returned.

                          When DABS (X) >= 2.6378256 x 107 , DCOS (X)
                          completely loses significance.  See Appendix A
                          for more details.

MPE/iX 5.0 Documentation