2110012504

Level: 
Project ID: 
2110012504
Source Problem: 
Accepted: 
0
Clonable: 
1
Easy: 
1
Choose the graph of a function $f$ that satisfies \begin{gather*} f'(1) \text{ does not exist}; \\ f''(x) < 0 \text{ if } x < 1 ; \\ f''(x) < 0 \text{ if } x > 2; \\ f''(x) > 0 \text{ if } 1 < x < 2 \end{gather*} ($f'$ is the derivative of a function $f$, $f''$ is the second derivative of a function $f$).