A rechargeable battery is plugged into a charger. The graph shows C(t), the percentage of full capacity that the battery reaches as a function of time t elapsed (in hours).

(a) What is the meaning of the derivative C’(t)?

(b) Sketch the graph of C’(t). What does the graph tell you?

Step 1 of 3

The meaning of derivative of is the ratio of change of percentage of full capacity in a very infinitesimal change of time.