(16 points) (b) Use a graphing utility (graphing calculator, online graphing tool, etc.) to graph the concentration function and use the graph to approximate the time when the concentration is greatest. (9 points) (c) Use calculus to determine analytically the exact time when the concentration is greatest. (30 points) (d) Find the exact time when the concentration increases at the greatest rate. (25 points) (e) Explain every step in your own words. (20 points)