Given f(x) = x2 + 2x + 9, find the average rate of change of f(x) over each of the following pairs of intervals. (a) [1.9, 2] and [1.99, 2] average rate of change over [1.9, 2] 5.9 Correct: Your answer is correct. average rate of change over [1.99, 2] 5.99 Correct: Your answer is correct. (b) [2, 2.1] and [2, 2.01] average rate of change over [2, 2.1] 6.1 Correct: Your answer is correct. average rate of change over [2, 2.01] 6.01 Correct: Your answer is correct. (c) What do the calculations in parts (a) and (b) suggest the instantaneous rate of change of f(x) at x = 2 might be?