Euler Four-Square Identity
The amazing polynomial identity
 | |
 | |
 |
in a letter to Goldbach on April 15, 1705. The identity also follows from the factthat the norm of the product of two Quaternions is the product of the norms (Conway and Guy 1996).See also Fibonacci Identity, Lagrange's Four-Square Theorem
References
Conway, J. H. and Guy, R. K. The Book of Numbers. New York: Springer-Verlag, p. 232, 1996. Petkovsek, M.; Wilf, H. S.; and Zeilberger, D. A=B. Wellesley, MA: A. K. Peters, p. 8, 1996.
- Substitution Map
- Subtend
- Subtraction
- Succeeds
- Successes
- Sufficient
- Suitable Number
- Sum
- Summand
- Summatory Function
- Sum-Product Number
- Sum Rule
- Sup
- Characteristic (Partial Differential Equation)
- Characteristic Polynomial
- Characteristic (Real Number)
- Character (Multiplicative)
- Character (Number Theory)
- Character Table
- Charlier's Check
- Chasles-Cayley-Brill Formula
- Chasles's Contact Theorem
- Chasles's Polars Theorem
- Chasles's Theorem
- Chebyshev Approximation Formula