I don’t quite understand the topic of differentiation… I’m not sure what dy/dx means and how it correlates to the topic..

What is the slope simplify your answer and write it as a proper fraction, improper fraction, or integer

You are on a cycling trip around europe with friends. you check the weather forecast for the first week. these are the temperatures for the week. sun mon tues wed thurs fri sat 16°c 20°c 24°c 28°c 28°c 23°c 15°c what is the mean temperature forecast for the week?

Which one is the correct answer, and why?