If the function y

If the function y = .018 t² + -2.5 t + 87 represents depth y vs. clock time t, then what is the average rate of depth change between clock times t = 17.7 and t = 35.4?

What is the rate of depth change at the clock time halfway between t = 17.7 and t = 35.4?

What function represents the rate r of depth change at clock time t?

What is the value of this function at the clock time halfway between t = 17.7 and t = 35.4?

If the rate of depth change is given by dy/dt = 9.500001E-02 t + -2.4 represents the rate at which depth is changing at clock time t, then how much depth change will there be between clock times t = 17.7 and t = 35.4?

Give the function that represents the depth. What would this specific function be if at clock time t = 0 the depth is 170?