15.8.2.18 Math.tan(x)

number Math.tan(x)

Return the tangent of x.

Math.tan = function(x){
x = ToNumber(x);
if (isNaN(x)) return NaN;
if (x === +0) return +0;
if (x === -0) return -0;
if (x == +Infinity) return NaN;
if (x == -Infinity) return NaN;
return Math.tan(x);
}