Z transform and its Application on Digital Signal Processing related Questions and Answers

Question :   Which of the following is true regarding the number of computations requires to compute an N-point DFT? 1. N2 complex multiplications and N(N-1) complex additions 2. N2 complex additions and N(N-1) complex multiplications 3. N2 complex multiplications and N(N+1) complex additions 4. N2 complex additions and N(N+1) complex multiplications Answer :   1 - N2 complex multiplications and N(N-1) complex additions