The Math.acos()
function returns the arccosine (in radians) of a number, that is
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Syntax
Math.acos(x)
Parameters
x
- A number representing a cosine, where x is between -1 and 1.
Return value
The arccosine (angle in radians) of the given number if it's between -1 and 1; otherwise, NaN
.
Description
The Math.acos()
method returns a numeric value between 0 and π radians for x
between -1 and 1. If the value of x
is outside this range, it returns NaN
.
Because acos()
is a static method of Math
, you always use it as Math.acos()
, rather than as a method of a Math
object you created (Math
is not a constructor).
Examples
Using Math.acos()
Math.acos(-2); // NaN Math.acos(-1); // 3.141592653589793 Math.acos(0); // 1.5707963267948966 Math.acos(0.5); // 1.0471975511965979 Math.acos(1); // 0 Math.acos(2); // NaN
For values less than -1 or greater than 1, Math.acos()
returns NaN
.
Specifications
Specification |
---|
ECMAScript (ECMA-262) The definition of 'Math.acos' in that specification. |
Browser compatibility
Desktop | Mobile | Server | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
acos | Chrome Full support 1 | Edge Full support 12 | Firefox Full support 1 | IE Full support 3 | Opera Full support 3 | Safari Full support 1 | WebView Android Full support 1 | Chrome Android Full support 18 | Firefox Android Full support 4 | Opera Android Full support 10.1 | Safari iOS Full support 1 | Samsung Internet Android Full support 1.0 | nodejs Full support 0.1.100 |
Legend
- Full support
- Full support