4.4: Reading Questions
What is the order of the element \(3\) in \(U(20)\text{?}\)
What is the order of the element \(5\) in \(U(23)\text{?}\)
Find three generators of \(\mathbb Z_8\text{.}\)
Find three generators of the \(5^\text{th}\) roots of unity.
Show how to compute \(15^{40}\pmod{23}\) efficiently by hand. Check your answer with Sage.