<html>
<body>
<h1>JavaScript Functions</h1>
<p>Invoke (call) a function that converts from Fahrenheit to Celsius:</p>
<p id="demo"></p>
<script>
function toCelsius(f) {
return (5/9) * (f-32);
}
let value = toCelsius(77);
document.getElementById("demo").innerHTML = value;
</script>
</body>
</html>