Hi, I have tried tackling these question but I am simply absolutely lost... 1. A single slit of width 1.50 um is illuminated with light of wavelength 500.0 nm. Find the angular width of the central maximum. I have no attempt for number 1. 2. Microwaves of wavelength 2.8 cm fall on a slit and the central maximum at a distance 2 m from the slit is found to have a half width of 0.67 m. Find the width of the slit. Well, I tried to find the angle by dividing 0.67/1. To find the slit width I then dividing 0.028 by 0.67. But my answer was wrong according to the book. Any help is appreciated. Thanks, Peter G.