First edition, 2026
Graph Theory by Inquiry
Eighteen chapters, from the first definitions of a graph to spectral graph theory.
Mathematics and computing, by inquiry
Earned
Earned
understanding.
Books and interactive lessons that hand you the question, not the answer, with just enough structure to work it out yourself.
One idea, two ways in
Built for people who would rather work it out.
Fedoruk makes learning materials in mathematics and computing for university students, self-learners and the instructors who teach them.
01
The By Inquiry books
Textbooks built from definitions and exercises. You prove the results yourself, one careful step at a time.
University students and self-learners
02
Interactive lessons
Lessons that ask you to commit to an answer before they show you one, starting with Calculus 1.
Students, and the instructors who teach them
Fedoruk Publishing
The books
The By Inquiry series is written in the tradition of inquiry-based learning: each book is a sequence of definitions and exercises that you work through, proving the theorems yourself.
2026
Recurrences by Inquiry
Sequences defined by their own earlier terms: find the pattern, solve the recurrence, prove it holds.
2026 · Assumes only high-school algebra
Induction by Inquiry
Weak and strong induction, well-ordering, structural induction, infinite descent, and a first look at the transfinite.
2026
Sorting by Inquiry
Twelve sorting algorithms, one per chapter: you prove each correct, trace it by hand and work out its running time, then survey the methods that remain.
2025
Applications for Linear Algebra: A Motivated Guide
Linear algebra, motivated by where it is used. For the student who keeps asking what it is for.
In preparation
- Combinatorics by Inquiry
- Inference by Inquiry
- Modular Arithmetic by Inquiry
The approach
The question comes first.
1
Start with a problem
Each idea arrives as a problem to work on, not a paragraph to read. Definitions and examples get you started; the discovery is yours.
2
You do the proving
The results are left for you to establish. A careful sequence of exercises makes each one reachable, and each one makes the next possible.
3
Hard things are called hard
Nothing is hand-waved and nothing pretends to be easy. When a step takes real effort, you are told so, because the effort is the point.
Fedoruk means understanding you earned yourself.
Interactive lessons
Calculus 1, one question at a time.
Twenty-nine interactive lessons on limits, derivatives and integrals. Each one starts with a question, gives you a graph to work with, and asks you to commit to an answer before it shows you one.
29lessons
3big ideas: limits, derivatives, integrals
For university instructors
Teaching an inquiry-based course?
Each By Inquiry book is a complete sequence of definitions and exercises, a natural spine for a course where students present and critique each other's proofs. If you are considering one for a course, write and ask about it.
About Fedoruk
Learning you earn, not receive.
Fedoruk is an educational brand built on inquiry-based learning. It publishes books for university students and self-learners, and interactive lessons, all in mathematics and computing.
Everything is written by Benjamin D. Fedoruk, who holds a BSc in Applied and Industrial Mathematics and an MEd and writes from Ontario, Canada.