Write a C# method (ElementFrequency) that determines how many times an element x is repeated in an array. You need to call this method in the Main Method .

Example:

Let a is an integer array where a = { 1, 4 ,3,2,6,3,2,7,5,2,3}

The method ElementFrequency (a,2) will return value 3 where the element 2 is repeated three times in the array a.

2- Write a C# method (IsSorted) that returns true if an array is sorted in increasing order and returns false otherwise. You need to call this method in the Main Method .

Example :

b={ 1,4,7,9,13} is sorted in increasing order. In this case, IsSorted(b) will return true.

c={ 1,4,7,9,8} is not sorted in increasing order. In this case, IsSorted(c) will return false.

3- Write C# method IsSymmetricArray that returns true if the array is symmetric and false otherwise. You need to call this method in the Main Method .

Example:

b={ 6,3,2,3,6} is symmetric. d= {6,3,3,6} is symmetric.

e= { 1,3,3,2} is not symmetric.

4- Using recursion, Write a method to find the value of f(n) given:

f(0)=2, f(1)=5

f(n) = f(n-1)+2f(n-2)+4, where n is Natural number

Display the value of f(5) in the Main method.