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

 sine

    OpenVMS usage:floating_point
    type:         F_floating, D_floating, G_floating
    access:       read only
    mechanism:    by reference

    Sine of the angle whose value (in degrees) is to be returned. The
    sine argument is the address of a floating-point number that is
    this sine. The absolute value of sine must be less than or equal
    to 1. For MTH$ASIND, sine specifies an F-floating number. For
    MTH$DASIND, sine specifies a D-floating number. For MTH$GASIND,
    sine specifies a G-floating number.