Math Path
MATH 01352 · Theory of Numbers

MATH 01352 · Divisibility & primes

Primes and infinitude proof idea

Definition

A prime has exactly two distinct positive divisors: 1 and itself. Euclid’s theorem: infinitely many primes — given p₁…pₖ, consider N=p₁…pₖ+1; a prime factor of N is new.

Read this

Variants produce primes in certain forms; the basic proof is must-know.

Prime gaps can be arbitrarily large even though primes are infinite.

Twin prime conjecture etc. are open — good cultural math.

Drill with flashcards

Flip through these until you can say the answer before revealing it.

Flashcards · 1 / 3

Click the card to flip

Try this

Attempt each problem first, then open the worked solution.

  1. 1.Write Euclid’s infinitude proof in your own words (paragraph).