title: Drawing the quadratic equation curve in c#
body: <p>I am very new to c# System Draw so please do help me on my code. i am trying to plot the quadratic equation curve and is using the "for" loop in order to dot 10 coordinates for the curve. i have tested out this code many times and nothing ever appears when i start the code. Also whenever i run the code, i get the message ArgumentException was Unhandled, Parameter is not valid with the code "  g.DrawCurve(aPen, Points);" highlighted. please help me on this problem i have spent many days trying to fix. </p>
  
  <pre><code>{
      public Form1()
      {
          InitializeComponent();
      }
  
      protected override void OnPaint(PaintEventArgs e)
      {
  
          float a = 10, b = 30, c = 10;
          double x1, x2, delta, cx1, cx2, y1, y2;
          int icx1, iy1, icx2, iy2;
          delta = (b * b) - (4 * a * c);
          x1 = ((b * (-1)) + Math.Sqrt(delta)) / (2 * a);
          x2 = ((b * (-1)) - Math.Sqrt(delta)) / (2 * a);
          for (int i = (-10); i &lt;= 10; i = i + 1)
          {
              cx1 = i * x1;
              cx2 = i * x2;
              y1 = (cx1 * cx1 * a) + (cx1 * b) + c;
              y2 = (cx2 * cx2 * a) + (cx2 * b) + c;
              icx1 = Convert.ToInt32(cx1);
              iy1 = Convert.ToInt32(y1);
              icx2 = Convert.ToInt32(cx2);
              iy2 = Convert.ToInt32(y2);
  
  
              Graphics g = e.Graphics;
              Pen aPen = new Pen(Color.Blue, 1);
              Point point1 = new Point(icx1, iy1);
              Point point2 = new Point(icx2, iy2);
              Point[] Points = { point1,point2 };
              g.DrawCurve(aPen, Points);
              aPen.Dispose();
              g.Dispose();
  
  
          }
  </code></pre>