4.Solve the following recurrences: a) T(n) = 2T(n-1) + 1 T(0)=0. b) T(n) = T(n-1) + n T(0)=1 5. Determine complexities of the following functions (Big-O): a. f(N) = () (N log N) + (log N)2 b. f(N) = N2(N + N log N + 1000) c. f(N) = N2 log N + 2N d. f(N) = ((?) (3N + 5+N) n))* (2N+5+N) e. f(N) = N f. f(N) = log10 2N g. f(N) = N! + 2N h. f(N) = (N * N * N * N + 2N)2