JSFiddle - React, Tailwind, and code Playground

HTML

<style>
  body {
    font-family: monospace;
    font-size: 14px;
    margin: 30px;
  }

</style>

<body>
  <script>
    function log(text) {
      var div = document.createElement("div");
      div.innerHTML = text;
      document.body.appendChild(div);
    }

    function test(val) {
      var series = 1 + val * (1 + val / (2*Math.PI) * (1 + val / (2 * Math.PI)**2));
      return series**2 * Math.pow(Math.E, -1 * Math.PI**2 / 2) - val;
    }

    // test Maple fsolve value
    log(test(0.007297352558));

    // test actual fine structure constant
    log(test(0.0072973525693));

    // test De Vries iterated value
    log(test(0.007297352568653856));


  </script>
</body>