š What is Hensel's Lemma?
Hensel's lemma is a powerful technique in number theory that allows us to "lift" solutions from modulo p to modulo p^k. It's like having a mathematical elevator!
The Main Idea: If we have a root r of polynomial f(x) modulo p, and the derivative f'(r) ⢠0 (mod p), then we can find a unique root modulo p² that reduces to r modulo p.
rk+1 = rk - f(rk) Ć [f'(rk)]-1 (mod pk+1)
This is essentially Newton's method in the p-adic numbers! Let's learn by solving problems together.
Level 1
Score: 0
šÆ Current Problem
Polynomial: f(x) = ?
Prime: p = ?
š Step 1: Find Roots Modulo p
First, let's find all roots of f(x) ā” 0 (mod p):