A bug on Markdown equation

[isboonto]

[fonsp]

Unfortunately this is an issue with Julia itself (md" is part of Julia), not with Pluto, so we can't fix it.

Try removing the spaces after the $.

You can also use the alternative math delimiters, they often work better with spaces:

[isboonto]

Thank you for your help. I find one method by using a slash before the subscript.

[fonsp]

Again, try removing the spaces around $

so $f(...)$ instead of $ f(...) $