(Typically actually \begin{align})
These are not, AFAICT, previewable. This is vexing because it is precisely these equations which are likely to be complex enough to need preview.
Is this feature on the RStudio roadmap? Or is it perhaps already in there and I just haven't noticed where?
I think this is the first time we've heard this request -- would you mind filing this as a feature request at https://github.com/rstudio/rstudio/issues, so we don't lose track of it?
Or, to turn this idea around, I wonder if it would be a useful feature for knitr/latex documents to also offer preview of the equations in RStudio IDE, i.e. support LaTeX equations in LaTeX documents even.