NAME
        IEEEDPSincos -- compute the arc tangent of a floating point number
   SYNOPSIS
          x   = IEEEDPSincos( z ,  y  );
        d0/d1                a0  d0/d1
        double  x,y,*z;
   FUNCTION
        Compute sin and cosine of y in IEEE double precision.
        Store the cosine in *z. Return the sine of y.
   INPUTS
        y - IEEE double precision floating point value
        z - pointer to IEEE double precision floating point number
   RESULT
        x - IEEE double precision floating point value
   BUGS
   SEE ALSO
        ieeedpsin(), ieeedpcos()