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JavaScript acos() Method

Math Object Reference JavaScript Math Object

Definition and Usage

The acos() method returns the arccosine of a number as a numeric value value between 0 and PI radians.

Syntax

Math.acos(x)

Parameter Description
x Required. Must be a numeric value in the range -1 to 1

Tips and Notes

Note: If the parameter x is outside the range -1 to 1, the browser will return NaN.

Note: -1 will return the value of PI.

Example

Example

Return the arccosine of different numbers:

<script type="text/javascript">

document.write(Math.acos(0.64) + "<br />");
document.write(Math.acos(0) + "<br />");
document.write(Math.acos(-1) + "<br />");
document.write(Math.acos(1) + "<br />");
document.write(Math.acos(2));

</script>

The output of the code above will be:

0.8762980611683406
1.5707963267948965
3.141592653589793
0
NaN

Try it yourself »

Math Object Reference JavaScript Math Object

From http://www.w3schools.com (Copyright Refsnes Data)