This one comes in two parts, but is basically the same question:

a) If , find and sketch the graphs of and . Where is not differentiable?

b) a) If , find and sketch the graphs of and . Where is not differentiable?

So, I believe that and , and know how to graph each of these functions. What I am not confident on is the part about where are these functions not differentiable? As I look at the graphs, it looks to me like they are both differentiable across all real numbers. Am I missing something?