Navigator 2.0, Internet Explorer 3.0
Math.asin(x)
A number or numeric expression between -1.0 and 1.0.
The arc sine, in radians, of the specified value x.
Math.asin() computes and returns the arc sine, or inverse sine of its argument. The argument must be a value between -1.0 and 1.0. The return value is between -pi/2 and pi/2 radians.