Problems for which there are no correct answers in the textbooks
Problems for which there is no correct answer in the textbook.
question with no correct answer.
Choice with no right answer
There is no right answer.
There is no right answer.
no textbook
Learning without textbooks
Learning what is not in the textbooks
Learning not found in textbooks.
Assumption that textbooks are correct
---
This page is auto-translated from /nishio/教科書に正解がない問題 using DeepL. If you looks something interesting but the auto-translated English is not good enough to understand it, feel free to let me know at @nishio_en. I'm very happy to spread my thought to non-Japanese readers.