# Dissemination of mistakes in international texts such as the IGCSE

I started tutoring IGCSE Mathematics. In preparation for just a 1 hour class for 1 student, I noticed at least 3 mistakes (confirmed with their replies to me) in Chapter 21 of the Haese 0607 book (quadratic equations and functions). I even noticed a mistake in the errata (last updated almost 2 years ago though I found the 3 mistakes in just 1 day) for a different chapter (probability).

Dumb question: How are these mistakes going to be disseminated?

I mean if I've noticed these mistakes, I wonder about all the other readers on Earth (students, teachers, tutors, parents, etc) who notice mistakes. I think it would be tiresome for both the authors to reply to the same mistakes and the readers to type up emails instead of having some dynamic errata (forum i guess).

• Did you already contact "www.igcsecentre.com"? – Dominique Nov 3 '17 at 12:15
• @Dominique For what exactly please? Also IGCSE is just an example. – BCLC Nov 3 '17 at 12:22
• I'm just curious. Could you provide at least one of the mistakes you found? – Joel Reyes Noche Nov 3 '17 at 13:24
• @JoelReyesNoche 1. Equates zero probability to impossibility 2. Left out $a \ne 0$, 3. Says 'the quadratic function' instead of 'any/a quadratic function' 4. Doesn't state properties of parabolas but expects students to know them (because while they say all graphs of quadratic functions are parabolas, there is no indication that all parabolas are graphs of quadratic functions) 5. (not sure) Vertical stretch rephrasing – BCLC Nov 3 '17 at 16:42
• Thanks. You ask "How are these mistakes going to be disseminated?" and then you link to an official errata document, so it seems you have an answer to your question. (By the way, the link to the errata in your post above doesn't work for me, but the link to the errata in your other question works for me.) – Joel Reyes Noche Nov 4 '17 at 0:56