I'm looking for a function with the following properties, and I'm wondering whether such a function exists. Let $I$ be an open interval, and let $c \in I $ be a point within that interval. I would like to find a function $f: I \to \mathbb{R} $ such that:
- Continuity: $𝑓$ is continuous on the entire interval $I$
- Zero at $𝑐$: $f(c)=0$
- Sign Change at $c$: $f$ changes sign at $𝑐$
- Monotonicity Change at $𝑐$: $f$ changes monotonicity $c$
Is it possible to construct such a function, and if so, what would an example look like? If not, why does such a function not exist?
Any insights would be appreciated.