much needed help!! Thank you

4. [6 pts] A small town in Ohio commissioned an actuarial rm to conduct a study that modeled the rate of change of the town's population. The study found that the town's population {measured in thousands of people] can be modeled by P(t) = r2 + 64t + seen, where t is time in years. a. Use the definition of the derivative to find Pr t . b. Find FIE). Interpret what the results mean for the town's population. c. Find PIS]. Interpret whatthe results mean for the town's population. 5. [6 pts] Scott throws his math textbook vertically from the edge of a cliff and watches as it goes up and then falls into the ocean below. The height ofthe book above the water [in meters} is a function of time and is given by Mt) = 4.9t2 + 34-: + 118, where t is in seconds. a. Find the velocity of the book after 5 seconds. Is the book rising or falling at this point? How do you know? b. Find the acceleration of the book at any time t. c. Find the velocity of the book when it hits the surface of the water