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Sources and credits

Isoline stands on open textbooks, generous photographers and open-source software. Here is who and what, with licenses.

Textbooks behind the tutor

The tutor searches excerpts from these openly licensed books and cites them when it uses them. Excerpts are shown with attribution under each book's license.

Course lessons

Every lesson, example and practice problem is written for Isoline, and practice answers are double-checked by independent calculations in the test suite.

  • Algebra, Calculus I to III and Differential Equations follow the topic order of Paul’s Online Math Notes , a sequence that matches most university courses.
  • Calculus II was cross-checked against the Simon Fraser University MATH 152 course notes (CC BY-NC-SA 4.0).
  • Probability & Statistics follows the chapter order of OpenStax Introductory Statistics (CC BY 4.0).

Going deeper

Each lab links to related sections for further reading.

The “Go deeper” links point to Paul’s Online Math Notes by Paul Dawkins. We link to his pages; none of his material is copied into Isoline or used by the tutor.

Photos

  • Car (edge detection lab): photo by Gabe Rodriguez on Unsplash
  • Escalator (edge detection lab): photo by Erez Attias on Unsplash
  • Lioness (edge detection lab): photo by Samuel Scrimshaw on Unsplash

Software

AI

The tutor runs on whichever models this site’s operator configures (for example Claude, or open models served by Groq, NVIDIA and OpenRouter). It can make mistakes, so check important work.