ASU MAT 243: Discrete Mathematical Structures
MAT 243 covers logic, proof techniques, set theory, functions and relations, induction, and combinatorics, the mathematical foundation for computer science. It's required for ASU CS majors and is most students' first encounter with writing proofs.
Fennie is independent and not affiliated with Arizona State University. This is an unofficial study guide.
What makes it hard
It's a different kind of math: instead of computing answers, you construct arguments, and there's no formula to fall back on. Proofs, especially induction, are the famous wall, and students who try to pattern-match homework solutions without understanding the logic get exposed on exams. It's frequently called the hidden weed-out of the ASU CS path.
What you'll cover
- • Propositional and predicate logic
- • Proof techniques (direct, contradiction, induction)
- • Set theory
- • Functions and relations
- • Combinatorics and counting
- • Intro graph theory
The MAT 243 study guide
How to study for ASU MAT 243, step by step.
- 1
Memorize definitions with total precision
Every MAT 243 proof starts from definitions, and 'roughly knowing' what a relation or an even integer is produces unprovable arguments. Be able to state each definition exactly, on demand.
- 2
Write one proof from scratch every day
Reading proofs feels productive and builds nothing. After studying an example, close it, reproduce the argument cold, then attempt a variant. That loop is the entire skill.
- 3
Start induction early and revisit it weekly
Induction is the course's famous wall and it yields only to repetition. Begin practicing the base-case/inductive-step structure weeks before it's examined, and keep a few reps in every study week.
- 4
Translate between English and logic notation daily
Quantifiers, implications, and negations underpin everything later. Five minutes a day converting statements both directions makes the proof units dramatically easier.
- 5
Explain your proofs out loud
If you can't justify why each line follows from the last, the proof is pattern-matched, not understood, and exams are built to expose exactly that. Talk through arguments with a study partner or to the wall.
Today
Today's MAT 243 plan
What a Fennie Daily Plan looks like for MAT 243. Yours is built from your own syllabus and adapts every day to your deadlines and progress.
First plan free, no card required. Fennie is independent and unaffiliated with your school.
FAQ
Is MAT 243 at ASU hard?
For most CS students it's the hardest math course so far, because it replaces computation with proof writing. The logic and counting units are manageable; induction and formal proofs require a mental shift that only practice produces.
How do I get better at proofs in MAT 243?
Write proofs from scratch daily, starting from the definitions. Reading solutions feels productive but doesn't build the skill. After studying an example, close it and reproduce the argument, then try a variant problem.
Why do CS majors need MAT 243?
Discrete math is the language of computer science: logic underlies program correctness, combinatorics underlies algorithm analysis, and graph theory underlies half of the data structures curriculum. Later CS theory courses assume all of it.
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