On the electrostatic potential and electric field of a uniformly charged disk

We calculate the electrostatic potential and electric field of a uniformly charged disk everywhere in space. This electrostatic problem was solved long ago, and its gravitational analogue - even earlier. However, it seems that physics students are not aware of the solution, because it is not presented in textbooks. The purpose of the present article is to fill this gap in the pedagogical literature.
Comment: 14 pages, 6 figures, to be published in European Journal of Physics