Take-home test in a survey course for nonmajors. And she referenced a book with a mistake. In my thirties, wanting to test out of college algebra, I bought som

Take-home test in a survey course for nonmajors. And she referenced a book with a mistake. In my thirties, wanting to test out of college algebra, I bought some math software to do drills and refresh my rusty high school math and the software had errors. It was fine for my purposes because I recognized the mistakes, but I was also homeschooling and I told my kids it probably wasn't a good resource for them because it has too many errors, so it wasn't something they should use for math practice. They didn't know enough math to recognize the errors and would have learned wrong. People make mistakes. This kind of scenario is always a possibility for an outsider with insufficient background knowledge to go "Wait ...that doesn't seem right." and, instead, just goes "But (famous expert) said it, so it must be true."