如何在该图中添加坐标轴？

我的任务是使用点数组绘制函数图。这是。

如何绘制坐标轴？

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 pr14
{
    public partial class Form2 : Form
    {
        protected override void OnPaint(PaintEventArgs e)
        { 
            // интервал
            const int minX = -2;
            const int maxX = 5;

            
            PointF[] points = new PointF[maxX - minX];
            for (int i = 0; i < points.Length; i++)
            {
                float x = i + minX;
                if (x <= 3)
                    points[i] = new PointF(x, 2 - x);
                else points[i] = new PointF(x, x * x);
            }

            //нормирование точек

            
            float w = this.ClientSize.Width;
            float h = this.ClientSize.Height;

            float minY = points[0].Y;
            float maxY = points[0].Y;
            for (int i = 1; i < points.Length; i++)
            {
                if (minY > points[i].Y) minY = points[i].Y;
                if (maxY < points[i].Y) maxY = points[i].Y;
            }

            for (int i = 0; i < points.Length; i++)
            {
                points[i].X = w * (points[i].X - minX) / (maxX - minX);
                points[i].Y = h - h * (points[i].Y - minY) / (maxY - minY);
            }

            e.Graphics.DrawLines(Pens.Blue, points);
        }
    }
}