Timeline for triangular matrix is invertible counterexample
Current License: CC BY-SA 4.0
13 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Nov 8, 2021 at 0:44 | history | removed from network questions | Asaf Karagila♦ | ||
| Nov 8, 2021 at 0:26 | history | became hot network question | |||
| Nov 7, 2021 at 16:41 | vote | accept | MCJ | ||
| Nov 7, 2021 at 16:39 | answer | added | Misha Lavrov | timeline score: 6 | |
| Nov 7, 2021 at 16:37 | comment | added | MCJ | yes, thank you! its not a counterexample, just a "example", | |
| Nov 7, 2021 at 16:36 | comment | added | TheSilverDoe | Indeed, if it is a typo and the real matrix is as @leslietownes says, then the book is correct. Except for the fact that the matrix is no longer a counterexample to the theorem, but just an example to it. | |
| Nov 7, 2021 at 16:32 | comment | added | MCJ | thank you so much, then this must be an error in the book! | |
| Nov 7, 2021 at 16:31 | comment | added | MCJ | hahah, i dont know if i miss something or what. but this book has a good reputation online, and it indeed explain things well | |
| Nov 7, 2021 at 16:31 | comment | added | leslie townes | Probably a typo. The matrix you put in the question is invertible. In the version of Anton and Rorres I just looked at (11th ed), there is almost this example, but with a $0$ (not a $2$) in the row 2, column 2 entry. | |
| Nov 7, 2021 at 16:28 | history | edited | MCJ | CC BY-SA 4.0 | added 1 character in body |
| Nov 7, 2021 at 16:27 | comment | added | TheSilverDoe | If the book really proves a theorem, and then gives a counterexample to it, then I would advise you to throw the book. | |
| S Nov 7, 2021 at 16:26 | review | First questions | |||
| Nov 7, 2021 at 16:28 | |||||
| S Nov 7, 2021 at 16:26 | history | asked | MCJ | CC BY-SA 4.0 |