Math 3345: Lecture Notes

Sections 26854 & 26835
Spring 2024
Max Kutler

These notes are the basis for our Math 3345 lectures. There may be material discussed in class which is not included in these notes, and vice versa.



Lecture 1: Logical sentences, negation, conjunction

Lecture 2: Disjunction, De Morgan's laws

Lecture 3: Distributive laws, implication

Lecture 4: Conditional and biconditional sentences, converse and contrapositive

Lecture 5: Conditional proof, tautologies, quantifiers

Lecture 6: Quantifiers

Lecture 7: Generalized De Morgan and distributive laws, order of quantifiers

Lecture 8: Unique existence, mathematical induction

Lecture 9: Induction

Lecture 10: Parity

Lecture 11: Axioms for the integers (also see the Integers handout)

Lecture 12: Basic consequences of the integer axioms, positive integers, inequalities

Lecture 13: The well-ordering principle, divisibility

Lecture 14: Divisibility

Lecture 15: Primes

Lecture 16: The infinitude of primes

Lecture 17: Division Algorithm

Lecture 18: Greatest common divisors, Euclidean Algorithm

Lecture 19: Reverse Euclidean Algorithm, congruence of integers

Lecture 20: Modular arithmetic

Lecture 21: More modular arithmetic

Lecture 22: The Fundamental Theorem of Arithmetic, the theorem on division by a prime

Lecture 23: Applications of FTA

Lecture 24: Proof of FTA

Lecture 25: Real, rational, and irrational numbers

Lecture 26: Square roots of integers

Lecture 27: Sets

Lecture 28: Subsets, algebra of sets

Lecture 29: DeMorgan's laws for sets, sets of sets, generalized unions and intersections

Lecture 30: Power sets, ordered pairs, Cartesian products

Lecture 31: Functions, graphs, function composition

Lecture 32: Surjections, injections, bijections (Zoom notes)

Lecture 33: Inverse functions

Lecture 34: More about inverse functions, cardinality

Lecture 35: Finite sets, pigeonhole principle

Lecture 36: Infinite sets, countability

Lecture 37: Uncountability of R