I understand LaTeX math is not supported. I'm looking for a recommendation on how to take math expressions, render them, and insert them into an answer on this site.
There are external editors like Codecogs which convert a LaTeX(-like) expression into an image, which you can then embed in your post (either directly or by uploading the image with the built-in image uploader).
You can use a function found here to actually view TeX in the site. Click on the first link to do so.
As said in the site, drag it to your bookmarks so you can reuse whenever you want.