# Does mathjax-latex work? Not entirely if Markdown is enabled.

I have updated to PhP 7.2 FastCGI and WordPress 5.2. I want to use WordPress to display markdown documents that have some latex, so I've installed a plugin for markdown which seems to work. However, I'm getting mixed results with "mathjax-latex". Perhaps markdown and mathjax-latex were not meant to cooperate, I will need to do more testing.

The main issue is that the LaTeX markup that does work in a markdown document that we export to HTML with, say pandoc, does not work "as is" with mathjax-latex. In particular, to get in-line math, special markup seems required.

I can easily show the result of failed efforts, but have difficulty showing the markup. The ordinary markdown code tricks, like indenting four spaces or enclosing in `, seem not to protect code from latex interpretation.

For inline math, the single dollar sign does not work. Observe, you see dollars $x_i$. However, writing the words "latex" within hard brackets "[" does work, along with "["/latex"]". The symbol "["latex"]" is converted to slash-paren, "\ (". Also I can explicitly type a double escaped "\\ (". Here is a gamma inserted inline with the first method: $$\gamma$$, and using the second method $$\gamma$$. Here is another Einstein favorite with the double-backslashed parenthesis: $$E=mc^2$$, but the single dollar sign is a dud $E=mc^2$. However, if I literally write '$latex' at the beginning, it works: $$E=mc^2$$. Here is an example where the dollar sign notation does not work: This x sub i is at the end of a line:$x_i$. That is a big disappointment because all of my example documents use that notation. Just now I wonder about using escapes, '\$x_i\\$'. Fail!

But if I put double dollar sign xsub i on line by itself, we get a displayed equation,

$$x_i$$

Double dollar signs work to get a display equation works OK if the dollar signs are on lines by themselves, which is happy news.

$$y_{i}\label{1b}$$

Bad news: the preferred LaTeX markup "$" does not work to give an inline equation: [ E = mc^2 ] To make that work, apparently I need a double back slash. That's unfortunate. Here is a double back slash hard bracket, to show it can work: \[E-mc^2$

I use double backslashed "" to try for a labeled/numbered display:

\gamma\label{eq:gam}

No number, and label doesn't work, trying to cross-reference, equation(\ref{eq:gam}) fails.

So, LaTeX that begins with a backslash apparently needs a double backslash, but that does not work for all \LaTeX, as you see from the fact that LaTeX is not displayed with any special markup.

## About pauljohn

Paul E. Johnson is a Professor of Political Science at the University of Kansas. He is an avid Linux User, an adequate system administrator and C programmer, and humility is one of his greatest strengths.
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