private void button2_Click(object sender, EventArgs e)
 {
     var funcs = new ChartFunction.MathFunction[] { Math.Sin, Math.Tan, Math.Ceiling, Math.Cos, Math.Atan };
     var fobj = new ChartFunction(chart1, funcs[rand.Next(funcs.Length)], Color.Black);
     // var fobj = new ChartFunction(chart1, Math.Ceiling, Color.Black);
     fobj.ExtendOnExtremum = true;
     fobj.Color = Color.Red;
     chart1.AddObject(fobj);
 }
        private void button2_Click(object sender, EventArgs e)
        {
            var funcs = new ChartFunction.MathFunction[] { Math.Sin, Math.Tan, Math.Ceiling, Math.Cos, Math.Atan };
            var fobj  = new ChartFunction(chart1, funcs[rand.Next(funcs.Length)], Color.Black);

            // var fobj = new ChartFunction(chart1, Math.Ceiling, Color.Black);
            fobj.ExtendOnExtremum = true;
            fobj.Color            = Color.Red;
            chart1.AddObject(fobj);
        }