The Attempt at a Solution
(b)θs=1.22(600nm)/30mm=24.4μm but what is spatial resolution and how to calculate it??
About the circle I was talking about, you can assume it to be centered at the center of the lens and since your image is located at the focal plane, the arc length of interest must touch the focal plane. What will r be?s=rθ, so what is r is this question?object distance? focal length?image distance?