For each local maximum $x=c$ in the following graph, approximate the largest possible $\delta>0$ so that $f(c) \geq f(x)$ for all $x \in(c-\delta, c+\delta)$. Similarly, for the one local minimum $x=b$, find the largest $\delta$ so that $f(b) \leq f(x)$ for all $x \in(b-\delta, b+\delta) .$