cdiv() returns the quotient of two complex numbers: (a + ib)/(c +
    id).

                           Entry-Point Names

    Generic                               Compaq
    Function   Data Type   OpenVMS        Tru64 UNIX
    Name       Required    Alpha          Alpha

    cdiv       S_FLOAT     math$cdiv_s    cdivf
               T_FLOAT     math$cdiv_t    cdiv
               X_FLOAT     math$cdiv_x    cdivl
               F_FLOAT     math$cdiv_f
               G_FLOAT     math$cdiv_g