A sample of radioactive Plutonium started with a mass of 16.2 mg. This isotope's half-life is 2.7 hours. a) Find a formula for the amount of Plutonium remaining after t hours. b) How long (from the original sample) will it take for the sample size to be down to only 1 mg ? c) Find the rate of change of decaying Plutonium after 1 hour. (4) 19. Use a diagram to draw 2a - 3b + c given the vectors shown. C 20. Suppose you are given the resultant and one vector in the addition of two vectors. How would you find the other vector? 21. Which is easier: adding vectors in Cartesian form or adding vectors in geometric form? Explain. 22. How can you tell if a function is continuous or discontinuous from its graph? 23. What response would you give to a classmate who makes the statement, "I do not need to learn the Product rule because I can always expand each product and then differentiate"