Please excuse us, there is ¡­

Please excuse us, there is a minor mistake in Mandatory Assignement 1, task 4 part 2: for an array of N infinitesimal-width elements separated by the pitch d, the total array aperture becomes (N-1)d, not Nd. [However when in addition each element has the extension d, the total aperture becomes N*d.]

We express our gratitude to the students who made us aware of the mistake.