1. Write a recursive function that returns the nth Fibonacci number from the Fibonacci series.
int fib(int n);
2. Write a recursive function to find the factorial of a number.
int factorial(int n);
3. Write a recursive function that returns the sum of the digits of an integer.
int sumOfDigits(int x);
4. Write a recursive function that find the minimum element in an array of integers.
int findMin(int a[], int size);
5. Write a recursive function that converts a decimal number to binary number.
int DecToBin(int dec);
6. Write a recursive function that find the sum of the following series.
1 + 1/2 + 1/4 + 1/8 + ... + 1/2n
