The name hitFactor does not exist in the current context

I'm getting error CS0103 for lines 17 and 31 both saying: "The name hitFactor does not exist in the current context" Thanks, I'm just getting started with C#

 using UnityEngine;
     using System.Collections;
     
     public class Ball : MonoBehaviour {
         // Speed to be modified in the Inspector
         public float speed = 2.0f;
         
         void Start() {
             // Give the ball some initial movement direction
             rigidbody2D.velocity = Vector2.one.normalized * speed;
         }
         
         void OnCollisionEnter2D(Collision2D col) {
             // Hit the left Racket?
             if (col.gameObject.name == "RacketLeft") {
                 // Calculate hit Factor
                 float y=hitFactor(transform.position,
                                   col.transform.position,
                                   ((BoxCollider2D)col.collider).size.y);
                 
                 // Calculate direction, set length to 1
                 Vector2 dir = new Vector2(1, y).normalized;
                 
                 // Set Velocity with dir * speed
                 rigidbody2D.velocity = dir * speed;
             }
             
             // Hit the right Racket?
             if (col.gameObject.name == "RacketRight") {
                 // Calculate hit Factor
                 float y=hitFactor(transform.position,
                                   col.transform.position,
                                   ((BoxCollider2D)col.collider).size.y);
                 
                 // Calculate direction, set length to 1
                 Vector2 dir = new Vector2(-1, y).normalized;
                 
                 // Set Velocity with dir * speed
                 rigidbody2D.velocity = dir * speed;
             }
         }
     }