Math.acos()
The Math.acos()
static method returns the inverse cosine (in radians) of a number. That is,
Try it
Syntax
js
Math.acos(x)
Parameters
x
-
A number between -1 and 1, inclusive, representing the angle's cosine value.
Return value
The inverse cosine (angle in radians between 0 and π, inclusive) of x
. If x
is less than -1 or greater than 1, returns NaN
.
Description
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()
js
Math.acos(-2); // NaN
Math.acos(-1); // 3.141592653589793 (π)
Math.acos(0); // 1.5707963267948966 (π/2)
Math.acos(0.5); // 1.0471975511965979 (π/3)
Math.acos(1); // 0
Math.acos(2); // NaN
Specifications
Specification |
---|
ECMAScript Language Specification # sec-math.acos |
Browser compatibility
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