Problem: The normal respiratory rate of an adult is roughly 12 to 20 breaths per minute. This means that an average adult will complete a breathing circle of inhaling and exhaling ap- proximately every 4 seconds. Our lungs can store a maximum of 6,000 ml of air when we take a full, deep breath and a minimum of 5,500 ml after an exhale. If at time t = 0 you have just exhaled then:
(A) Write a function that models the amount of air in your lungs.
(B) Draw a graph of the function.
(C) What is the amount of air in your lungs after 6 seconds? Explain your answers in detail including the graph.