Diffrentiation

Quote:

---

1. I'm given a piece-wise function graph and i'm to determine the value(s) of x where the function is not differentiable. How would i do this?

2. y . Determine the value(s) of x where the function is not differentiable.

3. At what points does the curve y have horizontal tangents?

---

I just need to know how what I have to do in each situation

1) function will not be differentiable at point where its not continuous.

2) function is not differentiable for points

3) curve has horizontal tangent at point y' = 0
i.e.