sqrt() computes the rounded square root of x.

    For platforms supporting a signed zero, sqrt(-0) = 0.

                           Entry-Point Names

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

    sqrt       S_FLOAT     math$sqrt_s    sqrtf
               T_FLOAT     math$sqrt_t    sqrt
               X_FLOAT     math$sqrt_x    sqrtl
               F_FLOAT     math$sqrt_f
               G_FLOAT     math$sqrt_g