Section 3.9, due Friday Oct 18

This section deals with taking square roots mod n.

1. Difficult: This section is pretty straightforward. I guess the hardest part was going back from the four solutions back to the factors of $n$, but it just took a second to understand why the difference of the roots is a multiple of one of the prime factors of $n$. This pretty simply leads to taking the gcd to find that prime factor, and then just dividing to get the other. 
2. Reflective: The most interesting part is the question at the beginning: how do we find square roots mod a prime which is 1 mod 4? Maybe worth tinkering with.