Now the amplitude here is related to the directional spreading function. Now how the directional spreading function how it is related half amplitude square is will be equal to the product of spectral directional spectrum into the delta f and delta three. So, here again you have n ranging there is the theta from n equal to 1 any number of components indicating the theta the directional components and f is the frequency components. Now you look at the equation three equations 3 the upper limit is infinity. So, that means you have a more number of that is the equation 3 as well as 5 it will become quite difficult to deal with from a practical point of view as they refer to infinitely large number of wavelengths.