The depth vs. clock time function y = .017 t2 + -1.6 t + 79 indicates the depth y of water in a certain uniform cylinder at clock time t.
What is the function that represents the rate r of depth change at clock time t?
If the rate of depth change is given by dy/dt = .049 t + -2.3 represents the rate at which depth is changing at clock time t, then how much depth change will there be between clock times t = 11.1 and t = 22.2?