Please help to see how to get this result, show me every single steps (The topic is diffraction)

Example 36.2 Single-slit diffraction: Intensity I (a) In a single-slit diffraction pattern, what is the intensity at a SET UP: The total phase difference between wavelets from the point where the total phase difference between wavelets from the two edges of the slit is the quantity we called B in Fig. 36.8d. top and bottom of the slit(is 66 rad? (b) If this point is 7.09 away Given B = 66 rad, we use Eq. (36.5) to find the intensity / at the from the central maximum, how many wavelengths wide is the point in question, and we use Eq. (36.6) to find the slit width a in slit? terms of the wavelength 1. SOLUTION EXECUTE: (a) Since B = 66 rad, B/2 = 33 rad and Eq. (36.5) DENTIFY: This problem asks us to find the intensity at a point in becomes single-slit diffraction pattern where there is a specified phase dif- rence between waves coming from the two edges of the slit sin ( 33 rad ) 2 1 = 10 33 rad = (9.2 X 10-4) 10 ig. 36.8a). It also asks us to relate phase difference, slit width, avelength, and the 0 shown in Fig. 36.9a