maths.free › Number Theory
Number Theory
Primes, divisibility, gcd, modular arithmetic and sequences.
Mësime
prime factorization of 360
Introductory
Prime numbers
Testing for primality by trial division up to the square root.
is 97 prime
Introductory
GCD and LCM
Euclid's algorithm and the identity gcd × lcm = a × b.
gcd(48, 18)
Core
Modular arithmetic
Remainders, congruences, fast powers and modular inverses.
3^100 mod 7
Introductory
Divisors
Counting and listing divisors from the prime factorisation.
divisors of 36
Core
Sequences
Fibonacci, recurrences and closed forms.
fib(20)
Introductory
Number bases
Converting between decimal, binary, octal and hexadecimal.
255 to binary
Core
Diophantine equations
Integer solutions: linear equations via Bézout, Pythagorean triples, Fermat.
gcd(12, 18)
Core
Fermat's little theorem and Euler's theorem
aᵖ⁻¹ ≡ 1 (mod p), the totient, and fast modular arithmetic.
2^100 mod 13
Advanced
RSA: cryptography from number theory
Public keys from two primes, and why factoring is the lock.
inverse of 17 mod 3120
The mathematics of whole numbers. Some of the oldest problems and the newest cryptography live here: factor a number into primes, run Euclid's algorithm, compute huge powers modulo a prime without ever writing the power down.
Mësime
Real Number Systems and Number Theory
Number Representation and Calculation
Divisibility
Congruences
Deeper water
Disa nga këto mësime janë përshtatur nga tekstet e hapura: OpenStax Contemporary Mathematics, Wikipedia. Çdo faqe mësimi emëron burimin dhe licencën e saj.
Simbolet e përdorura këtu
Prek çdo simbol për përkufizimin e plotë, një fotografi dhe se çfarë do të thotë çdo shkronjë në të.
Pyetja që bëjnë njerëzit
Why are primes so important?
Every integer factors into primes in exactly one way, so primes are the atoms of multiplication. Cryptography relies on that factoring being easy to state and hard to do.
How do I tell whether a big number is prime?
Trial division up to the square root works for small numbers. For large ones, probabilistic tests (Miller-Rabin) give an answer that is wrong with negligible probability, and deterministic tests (AKS) exist but are slower.
Shkruaj ose vizato në faqen e zgjidhjes: çdo hap, një fotografi, përgjigja e fshehur deri sa të pyesësh. Zgjidh →
Degë të tjera
+ Arithmetic𝑥 Algebra△ Geometry∿ Trigonometryƒ Precalculusσ Statistics & Probability⊢ Discrete Math & Logic∫ Calculus⊞ Linear Algebraẏ Differential Equations∇ Multivariable Calculusε Real Analysis⋔ Combinatorics & Graph Theory∈ Set Theory & Logic𝔾 Abstract Algebra𝑃 Probability Theory≈ Numerical Methodsℂ Complex Analysis◎ Topologyμ Measure Theory‖·‖ Functional Analysisκ Differential Geometryπ₁ Algebraic Topology→ Category Theory∂ Partial Differential Equations≋ Fluid Dynamics∞ Frontiers