Recitation of Apr. 9, 2013

We discussed problem 7.13 (a simple equivalence relation), example 7.25 (proving the well-known trick to figure out whether a number is divisible by 9). We worked on problem 7.1 (a related example).

Finally, we talked about Problem 7.22: Dirichlet's theorem for numbers of the form 4n + 3 and 5n + 6.