(a) If a single slit produces a first minimum at 14.5°, at what angle is the second-order minimum? 

(b) What is the angle of the third-order minimum? 

(c) Is there a fourth-order minimum? 

(d) Use your answers to illustrate how the angular width of the central maximum is about twice the angular width of the next maximum (which is the angle between the first and second minima).