PLEASE SOLVE AS SOON AS POSSIBLE

3 a) Suppose, you are asked to write an algorithm that returns the nth Fibonacci number. Here, 0,1, 1, 2, 3, 5, 8, ...... is a Fibonacci sequence with Fib(0) = 0. Write down a recursive algorithm to solve this problem. What is the disadvantage of this solution? b) Write down an algorithm to solve the issue in 3(a). Explain how the proposed solution solves the issue