Quadratic Invariant
Given the Binary Quadratic Form
 | (1) |
, let |  |  | (2) |
 | |  | (3) |
Then
 | (4) |
 | |  | (5) |
 | |  | (6) |
 | |  | (7) |
so
 | |
 | |
 | |
 | |
 | |
 | |
 | |
 | |
 | |
 | |
 | |
 | (8) |
. The quantity 
iscalled the Modulus.See also Algebraic Invariant- 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
- Chebyshev Constants