代码示例:(标识:jsck_atan)
<!DOCTYPE html>
<html>
<body>

<h1>JavaScript 数学</h1>

<p>Math.atan() 返回数的反正切:</p>

<p id="demo"></p>

<script>
document.getElementById("demo").innerHTML = Math.atan(2);
</script>

</body>
</html>
运行结果: