VMS Help RTL Routines, MTH$, MTH$HATAND, Arguments  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 h-degrees

    OpenVMS usage:floating_point
    type:         H_floating
    access:       write only
    mechanism:    by reference

    Angle (in degrees) whose tangent is specified by tangent. The
    h-degrees argument is the address of an H-floating number that
    is this angle. MTH$HATAND writes the address of the angle into
    h-degrees.

 tangent

    OpenVMS usage:floating_point
    type:         H_floating
    access:       read only
    mechanism:    by reference

    The tangent of the angle whose value (in degrees) is to be
    returned. The tangent argument is the address of a floating-point
    number that is this tangent. For MTH$HATAND, tangent specifies an
    H-floating number.