The graph provided shows the function $f(x)$, and you're asked to determine the points where the function is not differentiable.

In general, a function is not differentiable at points where:

1. There is a sharp corner or cusp.
2. There is a discontinuity.
3. The tangent becomes vertical.

Analysis of the graph:

• At $x = 0$: The graph has a smooth curve and appears continuous, meaning it is differentiable at this point. This explains why $x = 0$ is marked as differentiable (green checkmark).
• At $x = -2$: There seems to be a sharp corner, meaning the slope from the left and right are different. This is where the function is not differentiable.
• At $x = 2$: There is a cusp (sharp turning point), so the function is not differentiable here either.

Thus, the smaller value where $f(x)$ is not differentiable is $x = -2$.

Final answer:

• $x = -2$ (smaller value).
• $x = 2$ (already provided as the larger value is $x = 0$).

Let me know if you would like further details or have any questions!

Here are five related questions to expand your understanding:

1. What is the formal definition of differentiability at a point?
2. How do you determine the slope from a graph to identify a sharp corner?
3. Can a function be continuous but not differentiable?
4. What is the difference between a cusp and a vertical tangent in terms of differentiability?
5. How does the concept of limits relate to differentiability?

Tip: A smooth curve means the function is differentiable, while sharp changes in direction or breaks indicate non-differentiability.