
The JavaScript Math.acos() returns the arccosine of a number as a value between 0 and PI radians.
Syntax:
Math.acos(x);
x – a number.
Example:
<!DOCTYPE html>
<html>
<body>
<button onclick="acosExample()">Try it</button>
<p id="example-1"></p>
<script>
function acosExample() {
document.getElementById("example-1").innerHTML = Math.acos(0.8);
}
</script>
</body>
</html>
Output:
Click the button to display the arccosine of 0.8:
-1 will return the value of PI:
<!DOCTYPE html>
<html>
<body>
<button onclick="acosExample2()">Try it</button>
<p id="example-2"></p>
<script>
function acosExample2() {
document.getElementById("example-2").innerHTML = Math.acos(-1);
}
</script>
</body>
</html>
Output:
If the parameter x is outside the range -1 to 1, the method will return NaN:
<!DOCTYPE html>
<html>
<body>
<button onclick="acosExample3()">Try it</button>
<p id="example-3"></p>
<script>
function acosExample3() {
document.getElementById("example-3").innerHTML = Math.acos(1.2);
}
</script>
</body>
</html>
Output:
Enjoy coding!