PDF) A Simple Proof of Jacobi's Four-Square Theorem

Lagrange's four-square theorem, polynomials, diophantine equations, prime numbers

Lagrange's four-square theorem

Chapter 3 Greek Number Theory The Role of Number Theory Polygonal, Prime and Perfect Numbers The Euclidean Algorithm Pell's Equation The Chord and Tangent. - ppt download

Lagrange's three square theorem

Sum of two squares theorem - Wikipedia

Sum of Squares Function -- from Wolfram MathWorld

Proving the Pythagorean Theorem. Some algebraic and geometric proofs of…, by Michele Diodati, Not Zero

Waring's Problem -- from Wolfram MathWorld

MathType - Lagrange's four-square theorem states that every natural number can be represented as the sum of four integer squares. Proved by Joseph Louis #Lagrange in 1770, it can be regarded as

An Independent Quaternion Proof of Jacobi's Four Square Theorem