If the function y

If the function y = .017 t² + -1.4 t + 100 represents depth y vs. clock time t, then what is the average rate of depth change between clock times t = 10.5 and t = 21?

What is the rate of depth change at the clock time halfway between t = 10.5 and t = 21?

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 = 10.5 and t = 21?

If the rate of depth change is given by dy/dt = .224 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 = 10.5 and t = 21?

Give the function that represents the depth. What would this specific function be if at clock time t = 0 the depth is 190?