Построение графика функции

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
 
namespace WindowsFormsApp5
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
 
        private void button1_Click(object sender, EventArgs e)
        {
            MathGraph();
    }
        private void MathGraph()
        {
               const double t = 3.14;
            double shag = 0.1;
            double mashtab = 30;
 
            int fillHeight = 100;
            int fillWidth = 500;
            int otstup = 5;
            
            Graphics e = this.CreateGraphics();
            SolidBrush brush = new SolidBrush(Color.White);
            e.FillRectangle(brush, new Rectangle(otstup, otstup, fillWidth, fillHeight));
 
            int n = Convert.ToInt32(4*t / shag);
 
            Point[] pointW = new Point[n];
 
            int p = 0;
            for (double i = 0; i < 4*t; i += shag)
            {
                pointW[p] = new Point(Convert.ToInt32(i * mashtab + otstup), Convert.ToInt32(Math.Sin(i) * mashtab + (fillHeight / 2) + otstup));
                p++;
            }
            Pen pen = new Pen(Color.Black);
            e.DrawCurve(pen, pointW);
 
        }
 
    }
}

private double MyFunc(double a, double b, double c, double x)
{
    return a * Math.Pow(x, 3) + b * Math.Pow(x, 2) + c * x;
}

pointW[p] = new PointF(Convert.ToInt32(i * mashtab + otstup), Convert.ToInt32(Math.Sin(i) * mashtab + (fillHeight / 2) + otstup));