Calculate Projectile Range (C#, 2D project)

Hi, i found two formulas on internet which describes the way to calculate Range of a Projectile. First one is instantiating a trampoline in wrong location, and the second one is not instantiating nothing at all. I am just asking if anyone can help me with that. I will write below code that i wrote so far, so you can help me to debug it, or maybe you can give me another formula which will work.

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4.  
5. public class NextDropLocation : MonoBehaviour {
6.  
7.     public GameObject trampoline, player;
8.     float speed;
9.  
10.     float CalculateAngle()
11.     {
12.         var dir = player.transform.position;
13.         var angle = Mathf.Atan2(dir.y, dir.x) * Mathf.Rad2Deg;
14.         return angle;
15.     }
16.  
17.     private void FixedUpdate()
18.     {
19.         speed = player.GetComponent<Rigidbody2D>().velocity.magnitude;
20.     }
21.  
22.     float InstantiateNext(float speed, float angle)
23.     {
24.         return 2 * Mathf.Cos(angle) * speed * Mathf.Sqrt(2 * Mathf.Sin(angle) * speed / 9.81f); //This produces following error: transform.position assign attempt for 'mushroom2(Clone)' is not valid. Input position is { NaN, -3.650000, 0.000000 }.
25.         //return (Mathf.Pow(speed, 2) * 2 * Mathf.Sin(angle) * Mathf.Cos(angle) / 9.81f); //This instantiates trampoline in wrong location
26.     }
27.  
28.     private void OnCollisionEnter2D(Collision2D collision)
29.     {
30.         var angle = CalculateAngle();
31.         if (collision.gameObject.tag == "Mushroom")
32.         {
33.             player.GetComponent<Rigidbody2D>().AddForce(new Vector2(5, 5), ForceMode2D.Impulse);
34.             Instantiate(trampoline, new Vector3(InstantiateNext(speed, angle), -3.65f), player.transform.rotation);
35.  
36.         }
37.         else
38.             print("You landed on the ground. Game Over!");
39.     }
40.  
41.     // Use this for initialization
42.     void Start () {
43.         player = GameObject.FindGameObjectWithTag("Player");
44.        
45.     }
46.    
47.    
48. }
49.