JavaScript Math.acos() Method

　JavaScript Math Object

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

If the value of the passed parameter is-1to1outside the range, the method will return NaN.

Because acos() is a static method of Math, you should always use it asMath.acos(), rather than as a method of the Math object created.

Syntax:

Math.acos(x)

Math.acos(0.9);

Browser Compatibility

All browsers fully support the Math.acos() method:

Parameter Value

Technical Details

More examples

For less than-1or greater1The value, Math.acos() returns NaN:

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

　JavaScript Math Object