Hints

One can reuse the results established in Exercise 2 of Assignment 2. For Question $ (3)$ , you will need to take into account the cost of reducing modulo $ p$ the product $ f \, g$ computed in $ {\mbox{${\mathbb{Z}}$}}[x]$ , which means taking into account the cost of reducing each of these coefficients modulo $ p$ .

Marc Moreno Maza
2008-03-18