Quadratic Residues and the Legendre Symbol — Examples
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✓ 9 results · all verified · 5 also independently AI-judged
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1 · Prerequisites
Abstract Algebra
- Binary Operations, Monoids, Groups and Subgroups
- Cosets, Index and Lagrange's Theorem
- Cyclic Groups and Direct Products
- Group Homomorphisms and the Isomorphism Theorems
- Normal Subgroups and Quotient Groups
- Polynomial Rings, the Division Algorithm and Roots
- Rings, Subrings, Integral Domains and Fields
- The Fundamental Theorem of Finite Abelian Groups
Number Theory
Real Analysis
2 · Logical flowchart
3 · Items
Example
Quadratic residues, roots, and the Legendre table modulo 11
Example
Fourth and eighth powers modulo 17
Counterexample
Two quadratic nonresidues modulo 15 can have a nonresidue product
Example
The unique cube root of 2 modulo 29 is -3
Example
Euler's criterion computes (3/726377359) by repeated squaring
Example
The signed half-system for 3 modulo 11 gives (3/11)=1
Example
A nonmonic quadratic congruence solved through its discriminant
Counterexample
Squaring is not a homomorphism on a nonabelian group
Counterexample
A soluble square congruence need not define a quadratic residue
Sources
- W. Stein, Elementary Number Theory, Example 4.2.4
- A. Gorodnik, Number Theory, Lecture 9, Example 1.3
- H. Hackman, Elementary Number Theory, Chapter D, Section D.I
- N. Mascot, Legendre Symbols and Quadratic Reciprocity, Chapter 3
- W. Stein, Elementary Number Theory, Example 4.2.5
- H. Hackman, Elementary Number Theory, Chapter D, Section D.IV
- A. Gorodnik, Number Theory, Lecture 9, Section 1
- W. Stein, Elementary Number Theory, Section 4.1