该如何使用asp.net画出正弦曲线呢

 try
        {
            using (Bitmap sinImage = new Bitmap(360, 120))
            {

                using (Graphics myGraphics = Graphics.FromImage(sinImage))
                {

                    myGraphics.Clear(Color.White);
                    myGraphics.SmoothingMode = SmoothingMode.AntiAlias;
                    Rectangle r1 = new Rectangle(0, 0, 360, 20);
                    Rectangle r2 = new Rectangle(0, 20, 360, 40);
                    Rectangle r3 = new Rectangle(0, 60, 360, 40);
                    Rectangle r4 = new Rectangle(0, 100, 360, 20);

                    Brush brush1 = new SolidBrush(Color.White);
                    Brush brush2 = new SolidBrush(Color.SkyBlue);
                    Brush brush3 = new SolidBrush(Color.Pink);
                    Brush brush4 = new SolidBrush(Color.YellowGreen);