C＃三角函数使用

 public static double tricorn(double n, string str)
        {
            double pi = System.Math.PI;
            switch (str)
            {
                case "sin": return System.Math.Sin(n * pi / 180);
                case "cos": return System.Math.Cos(n * pi / 180);
                case "tan": return System.Math.Tan(n * pi / 180);
                case "cot": return 1.0 / System.Math.Tan(n * pi / 180);
                case "asin": return System.Math.Asin(n)*180/pi;
                case "acos": return System.Math.Acos(n))*180/pi;
                case "atan": return System.Math.Atan(n))*180/pi;
                case "acot": return System.Math.Atan(1.0 / n))*180/pi;
                default:
                    return 0;
            }
        }

C＃三角函数使用

原文：http://my.oschina.net/ucliaohh/blog/500582