HELP me please i am gettin "Assets/Weapon.cs(39,46): error CS1502: The best overloaded method match for `UnityEngine.Physics2D.Raycast(UnityEngine.Vector2, UnityEngine.Vector2, float, int, float)' has some invalid arguments"

using UnityEngine; using System.Collections;

public class Weapon : MonoBehaviour {

 public float fireRate = 0;
 public float Damage = 10;
 public LayerMask whatToHit;

 float timeToFire = 0;
 Transform firePoint;

 // Use this for initialization
 void Awake () {
     firePoint = transform.FindChild ("FirePoint");
     if (firePoint == null) {
         Debug.LogError ("No firePoint? WHAT?");
     }
 }
 
 // Update is called once per frame
 void Update () {
     if (fireRate == 0) {
         if (Input.GetButtonDown ("Fire1")) {
             Shoot ();
         }
     } 
     else {
         if (Input.GetButton ("Fire1") && Time.time > timeToFire)   {
             timeToFire = Time.time + 1 / fireRate;
             Shoot();
         }
     }
 }

 void Shoot () {
     Vector2 mousePosition = new Vector2 (Camera.main.ScreenToWorldPoint (Input.mousePosition).x, Camera.main.ScreenToWorldPoint(Input.mousePosition).y);
     Vector2 firePointPosition = new Vector2 (firePoint.position.x, firePoint.position.y);
     RaycastHit2D hit = Physics2D.Raycast (firePointPosition, mousePosition, mousePosition-firePointPosition, 100, whatToHit);
     Debug.DrawLine (firePointPosition, (mousePosition-firePointPosition)*100, Color.cyan);
     if (hit.collider != null)
         Debug.DrawLine (firePointPosition, hit.point, Color.red);
     Debug.Log ("We hit" + hit.collider.name + "and did " + Damage + " damage. ");
     }
 }

}