3 [20 Points] What does the following function compute? Derive the number of operations (work done) in this function when it is called with A[1 .. N]. Clearly show the recurrence relation, and the closed-form formula in terms of N.

int fun1 (int n)

{

if (n == 0)

return 1;

else

return fun1(n-1) + fun1(n-1);

}