15.8.2.2 Math.acos(x)

2010-07-24

number Math.acos(x:number|mixed)

Return arc cosine of x.

Result expressed in radians! In range of -π/2 to +π/2.

Code: (Meta Ecma)
Math.acos = function(x){
x = ToNumber(x);
if (isNaN(x)) return NaN;
if (x > 1) return NaN;
if (x < -1) return NaN;
if (x === 1) return +0;
return Math.acos(x);
}