An example of a symmetric function with an asymmetric minimum

For high school math olympiad students, OTIS XII applications are out , due August 1, 2026. But I’m really going to use that short announcement as an excuse to describe the second most common error I see on the OTIS application (the most common error is this type-error I wrote about in 2023 ). The mistake is so obvious I feel stupid writing about it, but I keep seeing it. So I’m going to record it…