JSFiddle - React, Tailwind, and code Playground

HTML

<form id='form-id'>
  <input id='watch-me' name='test' type='radio' /> Show Div<br />
  <input name='test' type='radio' /><br />
  <input name='test' type='radio' />
</form>
<div id='show-me' style='display:none'>Hello</div>

JavaScript

$('#form-id').change(function() {
    if ($('#watch-me').attr('checked')) {
        $('#show-me').show();
    } else {
        $('#show-me').hide();
    }
});