I have two questions here, 1. The two slits of a double slit each have a width of 0.140 mm and a distance between centers of 0.840 mm, (a) What orders are missing? (b) What is the approximate intensity of orders m=1 to m=3, relative to the zeroth-order maximum? 2. Sketch the intensity pattern for seven equally spaced slits having d/b = 3, Label points on the x-axis with the corresponding values of beta and gamma. For the first question, doesnt the missing orders depend on the wavelength? I don't have any clue on what equation to use. And for the second, I don't have any idea at all. Please help me in solving the questions, thanks!