title: How to use MathJax in an Rmarkdown github_document?
body: <p>I would like to include some math symbols in my GitHub README file generated by Rmarkdown. However, enclosing the symbols in <code>$</code> does not render them as symbols: it just puts parentheses around them. Based on <a href="https://rmarkdown.rstudio.com/github_document_format.html" rel="nofollow noreferrer">this document</a>, I thought perhaps I could use MathJax, but my efforts to get this to work have been unsuccessful so far. Any help would be appreciated!</p>
  
  <p><strong>Attempt 1:</strong></p>
  
  <pre><code>---
  output:
    github_document
  ---
  Here are some math symbols: $/alpha$ $A$ $1$ 
  </code></pre>
  
  <p><strong>Attempt 2:</strong></p>
  
  <pre><code>---
  output:
    github_document:
      pandoc_args: "--mathjax"
  ---
  Here are some math symbols: $/alpha$ $A$ $1$ 
  </code></pre>
  
  <p><strong>Attempt 3:</strong></p>
  
  <pre><code>---
  output:
    github_document:
      pandoc_args: [
        "--mathjax", "https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"
      ]
  ---
  Here are some math symbols: $/alpha$ $A$ $1$
  </code></pre>
  
  <p><strong>Attempt 4:</strong></p>
  
  <pre><code>---
  output:
    github_document:
      md_extensions: -tex_math_single_backslash+tex_math_dollars
  ---
  Here are some math symbols: $/alpha$ $A$ $1$
  </code></pre>
  
  <p>So far, all of these attempts produced this:</p>
  
  <p><a href="https://i.stack.imgur.com/ddlxG.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ddlxG.png" alt="enter image description here"></a></p>