Recently I read a couple of books with some of the following mistakes:
- Spelling
- Phrasing
- Scientific errors in equations
- Word duplications
- Other typography errors: formatting, missing colors, etc.
Should I bother reporting this to the authors? I do not want to be unpolite but some errors are severe and make the reading hard to understand. Would it matter anyway? Some books are in 3rd/4th edition and still contain these kind of mistakes.