JavaScript acos() method

Definition and usage

acos() The method returns the inverse cosine of a number, with a value between 0 and PI radians.

Note：If the parameter x If the value is outside the range of -1 to 1, this method will return NaN.

Tip：If the parameter x If the value is -1, then PI will be returned.

Example

Returns the inverse cosine of a number：

Math.acos(0.5);

Try it yourself

Syntax

Math.acos(x)

Parameter value

Parameter Description
x Required. It must be a number between -1.0 and 1.0.

Technical details

Return value： Numbers, from 0 to PI, if the value is outside the range of -1 to 1, it returns NaN.
JavaScript version： ECMAScript 1

Browser Support

Math.acos() Is an ES1 feature (JavaScript 1999). All browsers fully support it:

Chrome IE Edge Firefox Safari Opera
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Related Pages

Tutorial:JavaScript Math