Serving to educate or inform
See the instructive passage in Aristotle, Nic. Eth.
Yet instructive parallels may be found in ancient literatures.
The study of the clan-group as an organization is as instructive here as in other fields.
Burke's speech was more instructive than any other book on a political subject that I had ever read.
It may be instructive to contrast this with the case of an infinitely narrow annular aperture, where the brightness is proportional to Jo 2 (z).