# Some help with LaTeX and Preview on this forum please

Old Person
Hi.

I'm trying to get some mathematics on this forum. I've found this help article: https://www.physicsforums.com/help/latexhelp/
but.... it doesn't seem to working.

In that article the delimiters for a block of LaTeX are supposed to be hash tags or dollar symbols for example ## X^2 = 3 ## or $$X^2 = 3$$ and supposedly I can see the final display by clicking the preview button. Sadly, I don't - I just see the thing with the hash or dollar symbols. I've also tried $$x^2 = 3$$ since those start and end tags are used in some other forums. That didn't work either.

Any advice would be appreciated. Thank you.

Old Person
Ummm... for some reason, although it didn't work in the preview, it looks ok when posted.
is the preview feature broken? Is there no way to check the tex before posting?

Mentor
2022 Award
You have to update (F5) the page sometimes to give the interpreter a kick.

Old Person
Old Person
ok. Thank you. I will try that.

berkeman
Gold Member
2022 Award
Ummm... for some reason, although it didn't work in the preview, it looks ok when posted.
is the preview feature broken? Is there no way to check the tex before posting?
This is an old bug. See here: https://www.physicsforums.com/threads/latex-help.1046932/post-6816969

This can seriously mess up your equations if you write numerous equations and then refresh the page. The LaTeX will be rendered as symbols, and you will be left to cry, without an option to undo.

The workaround is to first write some simple LaTeX, like some simple Greek letters, and refresh the page. This will load the MathJax resource and LaTeX will start rendering. Now you may start writing what you want, and Preview will work well.

Old Person, topsquark, berkeman and 1 other person