Fibonacci.Please provide working out and explanation thank you.

2. Consider the following code to compute the n-th Fibonacci number. Fibonacci(n) if (n == 0) or (n == 1) { return n } else { return Fibonacci(n-1) + Fibonacci(n-2) Let Tn) denote the number of nodes in the computation tree that corresponds to the execution of the routine Fibonacci(n). (a) Express T(n) in a recursive form (see HW03 question (3), for example. Another example is the recursive definition of Fibonacci numbers). (b) Let the square brackets [:] denote the operation of rounding to the nearest integer. The n-th Fi- bonacci number (0 > n) can be obtained with the expression , where o = 1+X5. Alternatively, the n-th Fibonacci number is one on, where y = !=X5. Derive an exact expression for T(n)