public static double RF(
	double x,
	double y,
	double z
)Public Shared Function RF ( 
	x As Double,
	y As Double,
	z As Double
) As Doublepublic:
static double RF(
	double x, 
	double y, 
	double z
)static member RF : 
        x : float * 
        y : float * 
        z : float -> float