<!DOCTYPE html>
<html>
<body>
<p>Click the button to display the tangent of different numbers.</p>
<button onclick="myFunction()">Try it</button>
<p id="demo"></p>
<script>
function myFunction() {
var a = Math.tan(90);
var b = Math.tan(-90);
var c = Math.tan(45);
var d = Math.tan(60);
var x = a + "<br>" + b + "<br>" + c + "<br>" + d;
document.getElementById("demo").innerHTML = x;
}
</script>
</body>
</html>