As a pronunciation question about math, I think this sort of question sits in a gray area, and is acceptable in either place.
Where is it best suited? I think that depends on what the O.P. is trying to figure out.
If the O.P. is thinking:
I know how I'd say this in my native tongue, but I'm not sure how I would say it in English
then I have no problem with an English learner getting that help from ELL.
On the other hand, if the O.P. is thinking:
I'm pretty sure I know how to say this in English, but I'm presenting at the International Conference on Probability Theory next month, and I want to make sure I'm saying this
the way other mathematicians would say it
then it would probably be better suited for math.SE.
In other words: is the O.P. asking how the man on the street is likely to pronounce this equation? Or how it would be presented in the lecture halls of an engineering school?
Unfortunately, we don't always get a lot of background about why the O.P. is asking the question, or what level of information is being sought. When that information is absent, I tend to shy away from migrating, figuring that we'll let the O.P. ask where they are most comfortable asking, so long as the question is not blatently off-topic.
One footnote: I don't have any problem with someone leaving a comment making a newer user aware of other pertinent Stack Exchange sites. However, before suggesting migration, it's a good idea to visit the help center of the related site, and see how well the question would fit over there. In the case of math.SE, their help center says the site welcomes questions about:
- Understanding mathematical concepts and theorems
- Hints on mathematical problems
- History and development of mathematics
- Solving mathematical puzzles
- Software that mathematicians use
There's nothing in that list about pronouncing equations in English, so I think it's just as likely a regular at math.SE would suggest the question be migrated to one of the English forums. We want to be careful not to send a user on a wild goose chase, especially when there's a chance that this may ultimately be the best place to ask the question.