When copy and convert html to markdown, how to include latex in markdown?

[Norlandz]

For example

Given a website with html:

<div>
  Define the Function: Let
  <math xmlns="http://www.w3.org/1998/Math/MathML">
    <mrow>
      <mi>f</mi>
      <mo stretchy="false">(</mo>
      <mi>x</mi>
      <mo stretchy="false">)</mo>
      <mo>=</mo>
      <msup>
        <mi>x</mi>
        <mn>2</mn>
      </msup>
    </mrow>
  </math>
  , which has a <strong>derivative</strong>
  <math xmlns="http://www.w3.org/1998/Math/MathML">
    <mrow>
      <msup>
        <mi>f</mi>
        <mo rspace="0em" lspace="0em" mathvariant="normal">′</mo>
      </msup>
      <mo stretchy="false">(</mo>
      <mi>x</mi>
      <mo stretchy="false">)</mo>
      <mo>=</mo>
      <mn>2</mn>
      <mi>x</mi>
    </mrow>
  </math>
  .
</div>

When I copy & convert the html to markdown.

I want to include latex in markdown:

Define the function: Let $$ f(x) = x^2 $$, which has a **derivative** $$ f'(x) = 2x $$.

---

For clarification in case people dont know how latex works in html:

It is common to use latex in markdown. (eg: in RStudio, Ipynb, etc)
You can try to use https://upmath.me/ as online demo to see how it parses the latex in markdown.

The html I provided uses MathML for rendering formulas (latex),
so the whole point is to: Convert MathML code to Latex code.
Which is something very common, there should be many lib able to do this.