Very simple example of using mathjax in Javascript

PowerRule.js

<script>
//Day 2 learning Javascript 
//Very simple evaluation of a power rule - note, it's NOT a true evaluation: you can't check the answer correctly in the code this way.
    function Calculation(){
        let base = Math.floor((Math.random() * 100) + 1);
        let exp = Math.floor((Math.random() * 20) + 1);
        this.printQuestion = function(){
                    let calcString = `$$f(x)=${base}x^{${exp}}$$`;
                    document.writeln(calcString);
             };
        this.printAnswer= function(){
                    let answer = `$$${base * exp}x^{${exp - 1}}$$`;
                    document.getElementById('answer').innerHTML = answer;
                    MathJax.Hub.Queue(["Typeset",MathJax.Hub,'answer']); //must call MathJax on the element!
                    };
    }             
    var calc = new Calculation();
    calc.printQuestion();
    calc.printAnswer(); //called via onClick
</script>
    

Please note this is using es6 standards somewhat :)