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CSSStyleDeclaration

JavaScript acos() Method

< JavaScript Math Object

Example

Return the arccosine of a number:

Math.acos(0.5);

The result will be:

Try it Yourself »

Definition and Usage

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

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

Tip: -1 will return the value of PI.

Browser Support

Method
acos()	Yes	Yes	Yes	Yes	Yes

Syntax

Math.acos(x)

Parameter Values

Parameter	Description
x	Required. A number

Technical Details

Return Value:	A Number, from 0 to PI, or NaN if the value is outside the range of -1 to 1
JavaScript Version:	1.0

< JavaScript Math Object