I didn't run into any major problems with this activity. Students worked well on the first question and we had some good conversations about how much they could really tell about the graph of the derivative from the graph of the function. Many people drew the last derivative as a line (instead of a more cubic like shape) and we talked about how much we could justify at that point. This was a good point to come back to after the symbolic forms had been given and they had completed some numerical experimentation. I always like going back to the numerical experimentation during the rules to remind students what the derivative is so that they do not just become focused on rules at this point.