The help center's What types of questions should I avoid asking? says near the top that:
You should only ask practical, answerable questions based on actual problems that you face.
Full disclosure; I do not currently have a spacecraft in orbit around a planet who's apsidal precessions is a problem that I am facing.
In all honesty, I think that this question is simply interesting, that reading the answer will provide insight and understanding to me and future readers, and that another user will benefit both in reputation for posting an answer and just might learn something or have a "refresher" experience when they go back into the annals of perturbation theory to find out how the equation I've cited was originally derived and if any higher order terms were dropped.
This meta answer seems to suggest that each question I ask should satisfy the "actual problems that you face" criterion before I post it. Suppose we started applying that to every single question asked in this site, not just to me, but to all users, new and old, what would happen?
Isn't that realistically too high of a bar to set for asking questions here? What about users who are just interested in these topics for the pure joy of understanding, does this site's mission really exclude them?
I think that we should modify this working and remove "that you face". It serves no useful purpose, and if it were actually applied rigorously to each question the impact would be substantially negative.
Since when is intellectual pursuit for the pure joy of learning a bad reason to ask a Stack Exchange question?