asin() computes the principal value of the arc sine of x in the
    interval [-pi/2,pi/2] radians for x in the interval [-1,1].

    asind() computes the principal value of the arc sine of x in the
    interval [-90,90] degrees for x in the interval [-1,1].

                           Entry-Point Names

    Generic
    Function   Data Type   OpenVMS        Tru64 UNIX
    Name       Required

    asin       S_FLOAT     math$asin_s    asinf
               T_FLOAT     math$asin_t    asin
               X_FLOAT     math$asin_x    asinl
               F_FLOAT     math$asin_f
               G_FLOAT     math$asin_g

    asind      S_FLOAT     math$asind_s   asindf
               T_FLOAT     math$asind_t   asind
               X_FLOAT     math$asind_x   asindl
               F_FLOAT     math$asind_f
               G_FLOAT     math$asind_g