function sqrt(arg) {
        var result;

        // undefined inputs always return undefined
        if (typeof arg === 'undefined') {
            return undefined;
        }

        if (arg < 0) {
            throw {
                stack: (new Error()).stack,
                code: "D3060",
                index: 1,
                value: arg
            };
        }

        result = Math.sqrt(arg);

        return result;
    }
Square root of number
@param {Number} arg - Argument
@returns {Number} square root