they simply say that we need to include this script: <script src="[URL]https://polyfill.io/v3/polyfill.min.js?features=es6[/URL]"></script> <script id="MathJax-script" async src="[URL]https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js[/URL]"></script> and write our equations .. my questions: 1) is this script secure/safe? 2) will this always be free to use? 3) where can I find full MathJax equivalencies of all probable equations? Kind Regards